CWE

Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

CWE/SANS Top 25 Most Dangerous Software Errors
Home > CWE List > VIEW SLICE: CWE-702: Weaknesses Introduced During Implementation (3.0)  
ID

CWE VIEW: Weaknesses Introduced During Implementation

View ID: 702
Type: Implicit
Status: Incomplete
+ Objective
This view (slice) lists weaknesses that can be introduced during implementation.
+ Filter
/Weakness_Catalog/Weaknesses/Weakness[./Modes_Of_Introduction/Introduction/Phase='Implementation']
+ Membership
NatureTypeIDName
HasMemberVariantVariant5J2EE Misconfiguration: Data Transmission Without Encryption
HasMemberVariantVariant6J2EE Misconfiguration: Insufficient Session-ID Length
HasMemberVariantVariant7J2EE Misconfiguration: Missing Custom Error Page
HasMemberVariantVariant8J2EE Misconfiguration: Entity Bean Declared Remote
HasMemberVariantVariant9J2EE Misconfiguration: Weak Access Permissions for EJB Methods
HasMemberVariantVariant11ASP.NET Misconfiguration: Creating Debug Binary
HasMemberVariantVariant12ASP.NET Misconfiguration: Missing Custom Error Page
HasMemberVariantVariant13ASP.NET Misconfiguration: Password in Configuration File
HasMemberBaseBase14Compiler Removal of Code to Clear Buffers
HasMemberBaseBase15External Control of System or Configuration Setting
HasMemberClassClass20Improper Input Validation
HasMemberClassClass22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
HasMemberBaseBase23Relative Path Traversal
HasMemberVariantVariant24Path Traversal: '../filedir'
HasMemberVariantVariant25Path Traversal: '/../filedir'
HasMemberVariantVariant26Path Traversal: '/dir/../filename'
HasMemberVariantVariant27Path Traversal: 'dir/../../filename'
HasMemberVariantVariant28Path Traversal: '..\filedir'
HasMemberVariantVariant29Path Traversal: '\..\filename'
HasMemberVariantVariant30Path Traversal: '\dir\..\filename'
HasMemberVariantVariant31Path Traversal: 'dir\..\..\filename'
HasMemberVariantVariant32Path Traversal: '...' (Triple Dot)
HasMemberVariantVariant33Path Traversal: '....' (Multiple Dot)
HasMemberVariantVariant34Path Traversal: '....//'
HasMemberVariantVariant35Path Traversal: '.../...//'
HasMemberBaseBase36Absolute Path Traversal
HasMemberVariantVariant37Path Traversal: '/absolute/pathname/here'
HasMemberVariantVariant38Path Traversal: '\absolute\pathname\here'
HasMemberVariantVariant39Path Traversal: 'C:dirname'
HasMemberVariantVariant40Path Traversal: '\\UNC\share\name\' (Windows UNC Share)
HasMemberBaseBase41Improper Resolution of Path Equivalence
HasMemberVariantVariant42Path Equivalence: 'filename.' (Trailing Dot)
HasMemberVariantVariant43Path Equivalence: 'filename....' (Multiple Trailing Dot)
HasMemberVariantVariant44Path Equivalence: 'file.name' (Internal Dot)
HasMemberVariantVariant45Path Equivalence: 'file...name' (Multiple Internal Dot)
HasMemberVariantVariant46Path Equivalence: 'filename ' (Trailing Space)
HasMemberVariantVariant47Path Equivalence: ' filename' (Leading Space)
HasMemberVariantVariant48Path Equivalence: 'file name' (Internal Whitespace)
HasMemberVariantVariant49Path Equivalence: 'filename/' (Trailing Slash)
HasMemberVariantVariant50Path Equivalence: '//multiple/leading/slash'
HasMemberVariantVariant51Path Equivalence: '/multiple//internal/slash'
HasMemberVariantVariant52Path Equivalence: '/multiple/trailing/slash//'
HasMemberVariantVariant53Path Equivalence: '\multiple\\internal\backslash'
HasMemberVariantVariant54Path Equivalence: 'filedir\' (Trailing Backslash)
HasMemberVariantVariant55Path Equivalence: '/./' (Single Dot Directory)
HasMemberVariantVariant56Path Equivalence: 'filedir*' (Wildcard)
HasMemberVariantVariant57Path Equivalence: 'fakedir/../realdir/filename'
HasMemberVariantVariant58Path Equivalence: Windows 8.3 Filename
HasMemberBaseBase59Improper Link Resolution Before File Access ('Link Following')
HasMemberCompositeComposite61UNIX Symbolic Link (Symlink) Following
HasMemberVariantVariant62UNIX Hard Link
HasMemberVariantVariant65Windows Hard Link
HasMemberBaseBase66Improper Handling of File Names that Identify Virtual Resources
HasMemberVariantVariant67Improper Handling of Windows Device Names
HasMemberVariantVariant69Improper Handling of Windows ::DATA Alternate Data Stream
HasMemberVariantVariant72Improper Handling of Apple HFS+ Alternate Data Stream Path
HasMemberClassClass73External Control of File Name or Path
HasMemberClassClass74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
HasMemberClassClass75Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
HasMemberBaseBase76Improper Neutralization of Equivalent Special Elements
HasMemberClassClass77Improper Neutralization of Special Elements used in a Command ('Command Injection')
HasMemberBaseBase78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
HasMemberBaseBase79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
HasMemberVariantVariant80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
HasMemberVariantVariant81Improper Neutralization of Script in an Error Message Web Page
HasMemberVariantVariant82Improper Neutralization of Script in Attributes of IMG Tags in a Web Page
HasMemberVariantVariant83Improper Neutralization of Script in Attributes in a Web Page
HasMemberVariantVariant84Improper Neutralization of Encoded URI Schemes in a Web Page
HasMemberVariantVariant85Doubled Character XSS Manipulations
HasMemberVariantVariant86Improper Neutralization of Invalid Characters in Identifiers in Web Pages
HasMemberVariantVariant87Improper Neutralization of Alternate XSS Syntax
HasMemberBaseBase88Argument Injection or Modification
HasMemberBaseBase89Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
HasMemberBaseBase90Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
HasMemberBaseBase91XML Injection (aka Blind XPath Injection)
HasMemberBaseBase93Improper Neutralization of CRLF Sequences ('CRLF Injection')
HasMemberClassClass94Improper Control of Generation of Code ('Code Injection')
HasMemberBaseBase95Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
HasMemberBaseBase96Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')
HasMemberVariantVariant97Improper Neutralization of Server-Side Includes (SSI) Within a Web Page
HasMemberBaseBase98Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
HasMemberBaseBase99Improper Control of Resource Identifiers ('Resource Injection')
HasMemberVariantVariant102Struts: Duplicate Validation Forms
HasMemberVariantVariant103Struts: Incomplete validate() Method Definition
HasMemberVariantVariant104Struts: Form Bean Does Not Extend Validation Class
HasMemberVariantVariant105Struts: Form Field Without Validator
HasMemberVariantVariant106Struts: Plug-in Framework not in Use
HasMemberVariantVariant107Struts: Unused Validation Form
HasMemberVariantVariant108Struts: Unvalidated Action Form
HasMemberVariantVariant109Struts: Validator Turned Off
HasMemberVariantVariant110Struts: Validator Without Form Field
HasMemberBaseBase111Direct Use of Unsafe JNI
HasMemberBaseBase112Missing XML Validation
HasMemberBaseBase113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')
HasMemberBaseBase114Process Control
HasMemberBaseBase115Misinterpretation of Input
HasMemberClassClass116Improper Encoding or Escaping of Output
HasMemberBaseBase117Improper Output Neutralization for Logs
HasMemberClassClass118Incorrect Access of Indexable Resource ('Range Error')
HasMemberClassClass119Improper Restriction of Operations within the Bounds of a Memory Buffer
HasMemberBaseBase120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
HasMemberVariantVariant121Stack-based Buffer Overflow
HasMemberVariantVariant122Heap-based Buffer Overflow
HasMemberBaseBase123Write-what-where Condition
HasMemberBaseBase124Buffer Underwrite ('Buffer Underflow')
HasMemberBaseBase125Out-of-bounds Read
HasMemberVariantVariant126Buffer Over-read
HasMemberVariantVariant127Buffer Under-read
HasMemberBaseBase128Wrap-around Error
HasMemberBaseBase129Improper Validation of Array Index
HasMemberBaseBase130Improper Handling of Length Parameter Inconsistency
HasMemberBaseBase131Incorrect Calculation of Buffer Size
HasMemberBaseBase134Use of Externally-Controlled Format String
HasMemberBaseBase135Incorrect Calculation of Multi-Byte String Length
HasMemberClassClass138Improper Neutralization of Special Elements
HasMemberBaseBase140Improper Neutralization of Delimiters
HasMemberVariantVariant141Improper Neutralization of Parameter/Argument Delimiters
HasMemberVariantVariant142Improper Neutralization of Value Delimiters
HasMemberVariantVariant143Improper Neutralization of Record Delimiters
HasMemberVariantVariant144Improper Neutralization of Line Delimiters
HasMemberVariantVariant145Improper Neutralization of Section Delimiters
HasMemberVariantVariant146Improper Neutralization of Expression/Command Delimiters
HasMemberVariantVariant147Improper Neutralization of Input Terminators
HasMemberVariantVariant148Improper Neutralization of Input Leaders
HasMemberVariantVariant149Improper Neutralization of Quoting Syntax
HasMemberVariantVariant150Improper Neutralization of Escape, Meta, or Control Sequences
HasMemberVariantVariant151Improper Neutralization of Comment Delimiters
HasMemberVariantVariant152Improper Neutralization of Macro Symbols
HasMemberVariantVariant153Improper Neutralization of Substitution Characters
HasMemberVariantVariant154Improper Neutralization of Variable Name Delimiters
HasMemberVariantVariant155Improper Neutralization of Wildcards or Matching Symbols
HasMemberVariantVariant156Improper Neutralization of Whitespace
HasMemberVariantVariant157Failure to Sanitize Paired Delimiters
HasMemberVariantVariant158Improper Neutralization of Null Byte or NUL Character
HasMemberClassClass159Failure to Sanitize Special Element
HasMemberVariantVariant160Improper Neutralization of Leading Special Elements
HasMemberVariantVariant161Improper Neutralization of Multiple Leading Special Elements
HasMemberVariantVariant162Improper Neutralization of Trailing Special Elements
HasMemberVariantVariant163Improper Neutralization of Multiple Trailing Special Elements
HasMemberVariantVariant164Improper Neutralization of Internal Special Elements
HasMemberVariantVariant165Improper Neutralization of Multiple Internal Special Elements
HasMemberBaseBase166Improper Handling of Missing Special Element
HasMemberBaseBase167Improper Handling of Additional Special Element
HasMemberBaseBase168Improper Handling of Inconsistent Special Elements
HasMemberBaseBase170Improper Null Termination
HasMemberClassClass172Encoding Error
HasMemberVariantVariant173Improper Handling of Alternate Encoding
HasMemberVariantVariant174Double Decoding of the Same Data
HasMemberVariantVariant175Improper Handling of Mixed Encoding
HasMemberVariantVariant176Improper Handling of Unicode Encoding
HasMemberVariantVariant177Improper Handling of URL Encoding (Hex Encoding)
HasMemberBaseBase178Improper Handling of Case Sensitivity
HasMemberBaseBase179Incorrect Behavior Order: Early Validation
HasMemberBaseBase180Incorrect Behavior Order: Validate Before Canonicalize
HasMemberBaseBase181Incorrect Behavior Order: Validate Before Filter
HasMemberBaseBase182Collapse of Data into Unsafe Value
HasMemberBaseBase183Permissive Whitelist
HasMemberBaseBase184Incomplete Blacklist
HasMemberClassClass185Incorrect Regular Expression
HasMemberBaseBase186Overly Restrictive Regular Expression
HasMemberBaseBase187Partial Comparison
HasMemberBaseBase188Reliance on Data/Memory Layout
HasMemberBaseBase190Integer Overflow or Wraparound
HasMemberBaseBase191Integer Underflow (Wrap or Wraparound)
HasMemberClassClass192Integer Coercion Error
HasMemberBaseBase193Off-by-one Error
HasMemberBaseBase194Unexpected Sign Extension
HasMemberVariantVariant195Signed to Unsigned Conversion Error
HasMemberVariantVariant196Unsigned to Signed Conversion Error
HasMemberBaseBase197Numeric Truncation Error
HasMemberBaseBase198Use of Incorrect Byte Ordering
HasMemberClassClass200Information Exposure
HasMemberVariantVariant201Information Exposure Through Sent Data
HasMemberVariantVariant202Exposure of Sensitive Data Through Data Queries
HasMemberClassClass203Information Exposure Through Discrepancy
HasMemberBaseBase204Response Discrepancy Information Exposure
HasMemberBaseBase205Information Exposure Through Behavioral Discrepancy
HasMemberVariantVariant206Information Exposure of Internal State Through Behavioral Inconsistency
HasMemberVariantVariant207Information Exposure Through an External Behavioral Inconsistency
HasMemberBaseBase208Information Exposure Through Timing Discrepancy
HasMemberBaseBase209Information Exposure Through an Error Message
HasMemberBaseBase210Information Exposure Through Self-generated Error Message
HasMemberBaseBase211Information Exposure Through Externally-Generated Error Message
HasMemberBaseBase212Improper Cross-boundary Removal of Sensitive Data
HasMemberBaseBase213Intentional Information Exposure
HasMemberVariantVariant214Information Exposure Through Process Environment
HasMemberVariantVariant215Information Exposure Through Debug Information
HasMemberClassClass216Containment Errors (Container Errors)
HasMemberVariantVariant219Sensitive Data Under Web Root
HasMemberClassClass221Information Loss or Omission
HasMemberBaseBase222Truncation of Security-relevant Information
HasMemberBaseBase223Omission of Security-relevant Information
HasMemberBaseBase224Obscured Security-relevant Information by Alternate Name
HasMemberBaseBase226Sensitive Information Uncleared Before Release
HasMemberClassClass228Improper Handling of Syntactically Invalid Structure
HasMemberBaseBase229Improper Handling of Values
HasMemberVariantVariant230Improper Handling of Missing Values
HasMemberVariantVariant231Improper Handling of Extra Values
HasMemberVariantVariant232Improper Handling of Undefined Values
HasMemberBaseBase233Improper Handling of Parameters
HasMemberVariantVariant234Failure to Handle Missing Parameter
HasMemberVariantVariant235Improper Handling of Extra Parameters
HasMemberVariantVariant236Improper Handling of Undefined Parameters
HasMemberVariantVariant238Improper Handling of Incomplete Structural Elements
HasMemberVariantVariant239Failure to Handle Incomplete Element
HasMemberBaseBase240Improper Handling of Inconsistent Structural Elements
HasMemberBaseBase241Improper Handling of Unexpected Data Type
HasMemberBaseBase242Use of Inherently Dangerous Function
HasMemberVariantVariant243Creation of chroot Jail Without Changing Working Directory
HasMemberVariantVariant244Improper Clearing of Heap Memory Before Release ('Heap Inspection')
HasMemberVariantVariant245J2EE Bad Practices: Direct Management of Connections
HasMemberVariantVariant246J2EE Bad Practices: Direct Use of Sockets
HasMemberBaseBase248Uncaught Exception
HasMemberClassClass250Execution with Unnecessary Privileges
HasMemberBaseBase252Unchecked Return Value
HasMemberBaseBase253Incorrect Check of Function Return Value
HasMemberVariantVariant258Empty Password in Configuration File
HasMemberBaseBase259Use of Hard-coded Password
HasMemberVariantVariant260Password in Configuration File
HasMemberBaseBase266Incorrect Privilege Assignment
HasMemberBaseBase267Privilege Defined With Unsafe Actions
HasMemberBaseBase268Privilege Chaining
HasMemberClassClass269Improper Privilege Management
HasMemberBaseBase270Privilege Context Switching Error
HasMemberClassClass271Privilege Dropping / Lowering Errors
HasMemberBaseBase272Least Privilege Violation
HasMemberBaseBase273Improper Check for Dropped Privileges
HasMemberBaseBase274Improper Handling of Insufficient Privileges
HasMemberVariantVariant276Incorrect Default Permissions
HasMemberVariantVariant277Insecure Inherited Permissions
HasMemberVariantVariant279Incorrect Execution-Assigned Permissions
HasMemberBaseBase280Improper Handling of Insufficient Permissions or Privileges
HasMemberBaseBase281Improper Preservation of Permissions
HasMemberClassClass284Improper Access Control
HasMemberClassClass285Improper Authorization
HasMemberClassClass286Incorrect User Management
HasMemberClassClass287Improper Authentication
HasMemberVariantVariant289Authentication Bypass by Alternate Name
HasMemberBaseBase290Authentication Bypass by Spoofing
HasMemberBaseBase295Improper Certificate Validation
HasMemberVariantVariant302Authentication Bypass by Assumed-Immutable Data
HasMemberBaseBase303Incorrect Implementation of Authentication Algorithm
HasMemberBaseBase304Missing Critical Step in Authentication
HasMemberBaseBase305Authentication Bypass by Primary Weakness
HasMemberVariantVariant318Cleartext Storage of Sensitive Information in Executable
HasMemberBaseBase325Missing Required Cryptographic Step
HasMemberVariantVariant329Not Using a Random IV with CBC Mode
HasMemberClassClass330Use of Insufficiently Random Values
HasMemberBaseBase331Insufficient Entropy
HasMemberVariantVariant332Insufficient Entropy in PRNG
HasMemberVariantVariant333Improper Handling of Insufficient Entropy in TRNG
HasMemberBaseBase334Small Space of Random Values
HasMemberBaseBase335Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
HasMemberBaseBase336Same Seed in Pseudo-Random Number Generator (PRNG)
HasMemberBaseBase337Predictable Seed in Pseudo-Random Number Generator (PRNG)
HasMemberBaseBase338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
HasMemberBaseBase339Small Seed Space in PRNG
HasMemberClassClass340Predictability Problems
HasMemberBaseBase341Predictable from Observable State
HasMemberBaseBase342Predictable Exact Value from Previous Values
HasMemberBaseBase343Predictable Value Range from Previous Values
HasMemberBaseBase344Use of Invariant Value in Dynamically Changing Context
HasMemberClassClass345Insufficient Verification of Data Authenticity
HasMemberBaseBase346Origin Validation Error
HasMemberBaseBase347Improper Verification of Cryptographic Signature
HasMemberBaseBase348Use of Less Trusted Source
HasMemberBaseBase349Acceptance of Extraneous Untrusted Data With Trusted Data
HasMemberBaseBase351Insufficient Type Distinction
HasMemberBaseBase353Missing Support for Integrity Check
HasMemberBaseBase354Improper Validation of Integrity Check Value
HasMemberBaseBase356Product UI does not Warn User of Unsafe Actions
HasMemberBaseBase357Insufficient UI Warning of Dangerous Operations
HasMemberBaseBase358Improperly Implemented Security Check for Standard
HasMemberClassClass359Exposure of Private Information ('Privacy Violation')
HasMemberBaseBase360Trust of System Event Data
HasMemberClassClass362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
HasMemberBaseBase363Race Condition Enabling Link Following
HasMemberBaseBase364Signal Handler Race Condition
HasMemberBaseBase365Race Condition in Switch
HasMemberBaseBase366Race Condition within a Thread
HasMemberBaseBase367Time-of-check Time-of-use (TOCTOU) Race Condition
HasMemberBaseBase368Context Switching Race Condition
HasMemberBaseBase369Divide By Zero
HasMemberVariantVariant370Missing Check for Certificate Revocation after Initial Check
HasMemberBaseBase372Incomplete Internal State Distinction
HasMemberBaseBase374Passing Mutable Objects to an Untrusted Method
HasMemberBaseBase375Returning a Mutable Object to an Untrusted Caller
HasMemberBaseBase377Insecure Temporary File
HasMemberBaseBase378Creation of Temporary File With Insecure Permissions
HasMemberBaseBase379Creation of Temporary File in Directory with Incorrect Permissions
HasMemberVariantVariant382J2EE Bad Practices: Use of System.exit()
HasMemberVariantVariant383J2EE Bad Practices: Direct Use of Threads
HasMemberCompositeComposite384Session Fixation
HasMemberBaseBase385Covert Timing Channel
HasMemberBaseBase386Symbolic Name not Mapping to Correct Object
HasMemberClassClass390Detection of Error Condition Without Action
HasMemberBaseBase391Unchecked Error Condition
HasMemberBaseBase392Missing Report of Error Condition
HasMemberBaseBase393Return of Wrong Status Code
HasMemberBaseBase394Unexpected Status Code or Return Value
HasMemberBaseBase395Use of NullPointerException Catch to Detect NULL Pointer Dereference
HasMemberBaseBase396Declaration of Catch for Generic Exception
HasMemberBaseBase397Declaration of Throws for Generic Exception
HasMemberBaseBase400Uncontrolled Resource Consumption ('Resource Exhaustion')
HasMemberBaseBase401Improper Release of Memory Before Removing Last Reference ('Memory Leak')
HasMemberClassClass402Transmission of Private Resources into a New Sphere ('Resource Leak')
HasMemberBaseBase403Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')
HasMemberBaseBase404Improper Resource Shutdown or Release
HasMemberClassClass405Asymmetric Resource Consumption (Amplification)
HasMemberBaseBase406Insufficient Control of Network Message Volume (Network Amplification)
HasMemberBaseBase407Algorithmic Complexity
HasMemberBaseBase408Incorrect Behavior Order: Early Amplification
HasMemberBaseBase409Improper Handling of Highly Compressed Data (Data Amplification)
HasMemberBaseBase410Insufficient Resource Pool
HasMemberBaseBase412Unrestricted Externally Accessible Lock
HasMemberBaseBase413Improper Resource Locking
HasMemberBaseBase414Missing Lock Check
HasMemberVariantVariant415Double Free
HasMemberBaseBase416Use After Free
HasMemberBaseBase419Unprotected Primary Channel
HasMemberBaseBase420Unprotected Alternate Channel
HasMemberBaseBase425Direct Request ('Forced Browsing')
HasMemberCompositeComposite426Untrusted Search Path
HasMemberBaseBase427Uncontrolled Search Path Element
HasMemberBaseBase428Unquoted Search Path or Element
HasMemberBaseBase430Deployment of Wrong Handler
HasMemberBaseBase431Missing Handler
HasMemberBaseBase432Dangerous Signal Handler not Disabled During Sensitive Operations
HasMemberVariantVariant433Unparsed Raw Web Content Delivery
HasMemberBaseBase434Unrestricted Upload of File with Dangerous Type
HasMemberClassClass435Improper Interaction Between Multiple Entities
HasMemberBaseBase436Interpretation Conflict
HasMemberBaseBase437Incomplete Model of Endpoint Features
HasMemberBaseBase439Behavioral Change in New Version or Environment
HasMemberBaseBase440Expected Behavior Violation
HasMemberBaseBase444Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')
HasMemberBaseBase446UI Discrepancy for Security Feature
HasMemberBaseBase447Unimplemented or Unsupported Feature in UI
HasMemberBaseBase448Obsolete Feature in UI
HasMemberBaseBase449The UI Performs the Wrong Action
HasMemberBaseBase450Multiple Interpretations of UI Input
HasMemberClassClass451User Interface (UI) Misrepresentation of Critical Information
HasMemberBaseBase453Insecure Default Variable Initialization
HasMemberBaseBase454External Initialization of Trusted Variables or Data Stores
HasMemberBaseBase455Non-exit on Failed Initialization
HasMemberBaseBase456Missing Initialization of a Variable
HasMemberVariantVariant457Use of Uninitialized Variable
HasMemberBaseBase459Incomplete Cleanup
HasMemberVariantVariant460Improper Cleanup on Thrown Exception
HasMemberBaseBase462Duplicate Key in Associative List (Alist)
HasMemberBaseBase463Deletion of Data Structure Sentinel
HasMemberBaseBase464Addition of Data Structure Sentinel
HasMemberBaseBase466Return of Pointer Value Outside of Expected Range
HasMemberVariantVariant467Use of sizeof() on a Pointer Type
HasMemberBaseBase468Incorrect Pointer Scaling
HasMemberBaseBase469Use of Pointer Subtraction to Determine Size
HasMemberBaseBase470Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
HasMemberBaseBase471Modification of Assumed-Immutable Data (MAID)
HasMemberBaseBase472External Control of Assumed-Immutable Web Parameter
HasMemberVariantVariant473PHP External Variable Modification
HasMemberBaseBase474Use of Function with Inconsistent Implementations
HasMemberBaseBase475Undefined Behavior for Input to API
HasMemberBaseBase476NULL Pointer Dereference
HasMemberBaseBase477Use of Obsolete Function
HasMemberVariantVariant478Missing Default Case in Switch Statement
HasMemberVariantVariant479Signal Handler Use of a Non-reentrant Function
HasMemberBaseBase480Use of Incorrect Operator
HasMemberVariantVariant481Assigning instead of Comparing
HasMemberVariantVariant482Comparing instead of Assigning
HasMemberVariantVariant483Incorrect Block Delimitation
HasMemberBaseBase484Omitted Break Statement in Switch
HasMemberVariantVariant486Comparison of Classes by Name
HasMemberVariantVariant487Reliance on Package-level Scope
HasMemberVariantVariant488Exposure of Data Element to Wrong Session
HasMemberBaseBase489Leftover Debug Code
HasMemberVariantVariant491Public cloneable() Method Without Final ('Object Hijack')
HasMemberVariantVariant492Use of Inner Class Containing Sensitive Data
HasMemberVariantVariant493Critical Public Variable Without Final Modifier
HasMemberBaseBase494Download of Code Without Integrity Check
HasMemberVariantVariant495Private Array-Typed Field Returned From A Public Method
HasMemberVariantVariant496Public Data Assigned to Private Array-Typed Field
HasMemberVariantVariant497Exposure of System Data to an Unauthorized Control Sphere
HasMemberVariantVariant498Cloneable Class Containing Sensitive Information
HasMemberVariantVariant499Serializable Class Containing Sensitive Data
HasMemberVariantVariant500Public Static Field Not Marked Final
HasMemberVariantVariant502Deserialization of Untrusted Data
HasMemberClassClass506Embedded Malicious Code
HasMemberBaseBase507Trojan Horse
HasMemberBaseBase508Non-Replicating Malicious Code
HasMemberBaseBase509Replicating Malicious Code (Virus or Worm)
HasMemberBaseBase510Trapdoor
HasMemberBaseBase511Logic/Time Bomb
HasMemberBaseBase512Spyware
HasMemberClassClass514Covert Channel
HasMemberBaseBase515Covert Storage Channel
HasMemberVariantVariant520.NET Misconfiguration: Use of Impersonation
HasMemberBaseBase521Weak Password Requirements
HasMemberBaseBase522Insufficiently Protected Credentials
HasMemberVariantVariant524Information Exposure Through Caching
HasMemberVariantVariant525Information Exposure Through Browser Caching
HasMemberVariantVariant526Information Exposure Through Environmental Variables
HasMemberVariantVariant532Information Exposure Through Log Files
HasMemberVariantVariant533Information Exposure Through Server Log Files
HasMemberVariantVariant535Information Exposure Through Shell Error Message
HasMemberVariantVariant536Information Exposure Through Servlet Runtime Error Message
HasMemberVariantVariant537Information Exposure Through Java Runtime Error Message
HasMemberBaseBase538File and Directory Information Exposure
HasMemberVariantVariant539Information Exposure Through Persistent Cookies
HasMemberVariantVariant540Information Exposure Through Source Code
HasMemberVariantVariant541Information Exposure Through Include Source Code
HasMemberVariantVariant542Information Exposure Through Cleanup Log Files
HasMemberVariantVariant543Use of Singleton Pattern Without Synchronization in a Multithreaded Context
HasMemberVariantVariant546Suspicious Comment
HasMemberVariantVariant547Use of Hard-coded, Security-relevant Constants
HasMemberVariantVariant548Information Exposure Through Directory Listing
HasMemberVariantVariant549Missing Password Field Masking
HasMemberVariantVariant550Information Exposure Through Server Error Message
HasMemberBaseBase551Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
HasMemberBaseBase552Files or Directories Accessible to External Parties
HasMemberVariantVariant553Command Shell in Externally Accessible Directory
HasMemberVariantVariant554ASP.NET Misconfiguration: Not Using Input Validation Framework
HasMemberVariantVariant555J2EE Misconfiguration: Plaintext Password in Configuration File
HasMemberVariantVariant556ASP.NET Misconfiguration: Use of Identity Impersonation
HasMemberVariantVariant558Use of getlogin() in Multithreaded Application
HasMemberVariantVariant560Use of umask() with chmod-style Argument
HasMemberVariantVariant561Dead Code
HasMemberBaseBase562Return of Stack Variable Address
HasMemberVariantVariant563Assignment to Variable without Use
HasMemberVariantVariant564SQL Injection: Hibernate
HasMemberBaseBase565Reliance on Cookies without Validation and Integrity Checking
HasMemberVariantVariant566Authorization Bypass Through User-Controlled SQL Primary Key
HasMemberBaseBase567Unsynchronized Access to Shared Data in a Multithreaded Context
HasMemberVariantVariant568finalize() Method Without super.finalize()
HasMemberVariantVariant570Expression is Always False
HasMemberVariantVariant571Expression is Always True
HasMemberVariantVariant572Call to Thread run() instead of start()
HasMemberClassClass573Improper Following of Specification by Caller
HasMemberVariantVariant574EJB Bad Practices: Use of Synchronization Primitives
HasMemberVariantVariant575EJB Bad Practices: Use of AWT Swing
HasMemberVariantVariant576EJB Bad Practices: Use of Java I/O
HasMemberVariantVariant577EJB Bad Practices: Use of Sockets
HasMemberVariantVariant578EJB Bad Practices: Use of Class Loader
HasMemberVariantVariant579J2EE Bad Practices: Non-serializable Object Stored in Session
HasMemberVariantVariant580clone() Method Without super.clone()
HasMemberBaseBase581Object Model Violation: Just One of Equals and Hashcode Defined
HasMemberVariantVariant582Array Declared Public, Final, and Static
HasMemberVariantVariant583finalize() Method Declared Public
HasMemberBaseBase584Return Inside Finally Block
HasMemberVariantVariant585Empty Synchronized Block
HasMemberVariantVariant586Explicit Call to Finalize()
HasMemberBaseBase587Assignment of a Fixed Address to a Pointer
HasMemberVariantVariant588Attempt to Access Child of a Non-structure Pointer
HasMemberVariantVariant589Call to Non-ubiquitous API
HasMemberVariantVariant590Free of Memory not on the Heap
HasMemberVariantVariant591Sensitive Data Storage in Improperly Locked Memory
HasMemberVariantVariant593Authentication Bypass: OpenSSL CTX Object Modified after SSL Objects are Created
HasMemberVariantVariant594J2EE Framework: Saving Unserializable Objects to Disk
HasMemberBaseBase595Comparison of Object References Instead of Object Contents
HasMemberBaseBase596Incorrect Semantic Object Comparison
HasMemberVariantVariant597Use of Wrong Operator in String Comparison
HasMemberVariantVariant598Information Exposure Through Query Strings in GET Request
HasMemberVariantVariant599Missing Validation of OpenSSL Certificate
HasMemberBaseBase600Uncaught Exception in Servlet
HasMemberVariantVariant601URL Redirection to Untrusted Site ('Open Redirect')
HasMemberBaseBase603Use of Client-Side Authentication
HasMemberBaseBase605Multiple Binds to the Same Port
HasMemberBaseBase606Unchecked Input for Loop Condition
HasMemberVariantVariant607Public Static Final Field References Mutable Object
HasMemberVariantVariant608Struts: Non-private Field in ActionForm Class
HasMemberBaseBase609Double-Checked Locking
HasMemberVariantVariant611Improper Restriction of XML External Entity Reference ('XXE')
HasMemberVariantVariant612Information Exposure Through Indexing of Private Data
HasMemberBaseBase613Insufficient Session Expiration
HasMemberVariantVariant614Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
HasMemberVariantVariant615Information Exposure Through Comments
HasMemberVariantVariant616Incomplete Identification of Uploaded File Variables (PHP)
HasMemberVariantVariant617Reachable Assertion
HasMemberBaseBase618Exposed Unsafe ActiveX Method
HasMemberBaseBase619Dangling Database Cursor ('Cursor Injection')
HasMemberVariantVariant620Unverified Password Change
HasMemberBaseBase621Variable Extraction Error
HasMemberVariantVariant622Improper Validation of Function Hook Arguments
HasMemberVariantVariant623Unsafe ActiveX Control Marked Safe For Scripting
HasMemberBaseBase624Executable Regular Expression Error
HasMemberBaseBase625Permissive Regular Expression
HasMemberVariantVariant626Null Byte Interaction Error (Poison Null Byte)
HasMemberBaseBase627Dynamic Variable Evaluation
HasMemberBaseBase628Function Call with Incorrectly Specified Arguments
HasMemberClassClass636Not Failing Securely ('Failing Open')
HasMemberClassClass637Unnecessary Complexity in Protection Mechanism (Not Using 'Economy of Mechanism')
HasMemberClassClass638Not Using Complete Mediation
HasMemberBaseBase640Weak Password Recovery Mechanism for Forgotten Password
HasMemberBaseBase641Improper Restriction of Names for Files and Other Resources
HasMemberClassClass642External Control of Critical State Data
HasMemberBaseBase643Improper Neutralization of Data within XPath Expressions ('XPath Injection')
HasMemberVariantVariant644Improper Neutralization of HTTP Headers for Scripting Syntax
HasMemberVariantVariant646Reliance on File Name or Extension of Externally-Supplied File
HasMemberVariantVariant647Use of Non-Canonical URL Paths for Authorization Decisions
HasMemberBaseBase648Incorrect Use of Privileged APIs
HasMemberBaseBase649Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking
HasMemberVariantVariant650Trusting HTTP Permission Methods on the Server Side
HasMemberVariantVariant651Information Exposure Through WSDL File
HasMemberBaseBase652Improper Neutralization of Data within XQuery Expressions ('XQuery Injection')
HasMemberBaseBase653Insufficient Compartmentalization
HasMemberBaseBase654Reliance on a Single Factor in a Security Decision
HasMemberBaseBase655Insufficient Psychological Acceptability
HasMemberBaseBase656Reliance on Security Through Obscurity
HasMemberClassClass657Violation of Secure Design Principles
HasMemberBaseBase662Improper Synchronization
HasMemberBaseBase663Use of a Non-reentrant Function in a Concurrent Context
HasMemberClassClass664Improper Control of a Resource Through its Lifetime
HasMemberClassClass665Improper Initialization
HasMemberBaseBase666Operation on Resource in Wrong Phase of Lifetime
HasMemberBaseBase667Improper Locking
HasMemberClassClass668Exposure of Resource to Wrong Sphere
HasMemberClassClass669Incorrect Resource Transfer Between Spheres
HasMemberClassClass670Always-Incorrect Control Flow Implementation
HasMemberClassClass671Lack of Administrator Control over Security
HasMemberBaseBase672Operation on a Resource after Expiration or Release
HasMemberClassClass673External Influence of Sphere Definition
HasMemberBaseBase674Uncontrolled Recursion
HasMemberClassClass675Duplicate Operations on Resource
HasMemberBaseBase676Use of Potentially Dangerous Function
HasMemberClassClass681Incorrect Conversion between Numeric Types
HasMemberClassClass682Incorrect Calculation
HasMemberVariantVariant683Function Call With Incorrect Order of Arguments
HasMemberClassClass684Incorrect Provision of Specified Functionality
HasMemberVariantVariant685Function Call With Incorrect Number of Arguments
HasMemberVariantVariant686Function Call With Incorrect Argument Type
HasMemberVariantVariant687Function Call With Incorrectly Specified Argument Value
HasMemberVariantVariant688Function Call With Incorrect Variable or Reference as Argument
HasMemberCompositeComposite689Permission Race Condition During Resource Copy
HasMemberChainChain690Unchecked Return Value to NULL Pointer Dereference
HasMemberClassClass691Insufficient Control Flow Management
HasMemberClassClass693Protection Mechanism Failure
HasMemberBaseBase694Use of Multiple Resources with Duplicate Identifier
HasMemberBaseBase695Use of Low-Level Functionality
HasMemberClassClass696Incorrect Behavior Order
HasMemberClassClass697Insufficient Comparison
HasMemberBaseBase698Execution After Redirect (EAR)
HasMemberClassClass703Improper Check or Handling of Exceptional Conditions
HasMemberClassClass704Incorrect Type Conversion or Cast
HasMemberClassClass705Incorrect Control Flow Scoping
HasMemberClassClass706Use of Incorrectly-Resolved Name or Reference
HasMemberClassClass707Improper Enforcement of Message or Data Structure
HasMemberBaseBase708Incorrect Ownership Assignment
HasMemberClassClass710Improper Adherence to Coding Standards
HasMemberClassClass732Incorrect Permission Assignment for Critical Resource
HasMemberBaseBase749Exposed Dangerous Method or Function
HasMemberClassClass754Improper Check for Unusual or Exceptional Conditions
HasMemberClassClass755Improper Handling of Exceptional Conditions
HasMemberBaseBase759Use of a One-Way Hash without a Salt
HasMemberBaseBase760Use of a One-Way Hash with a Predictable Salt
HasMemberVariantVariant761Free of Pointer not at Start of Buffer
HasMemberVariantVariant762Mismatched Memory Management Routines
HasMemberBaseBase763Release of Invalid Pointer or Reference
HasMemberVariantVariant764Multiple Locks of a Critical Resource
HasMemberVariantVariant765Multiple Unlocks of a Critical Resource
HasMemberVariantVariant766Critical Variable Declared Public
HasMemberVariantVariant767Access to Critical Private Variable via Public Method
HasMemberVariantVariant768Incorrect Short Circuit Evaluation
HasMemberBaseBase769Uncontrolled File Descriptor Consumption
HasMemberBaseBase770Allocation of Resources Without Limits or Throttling
HasMemberBaseBase771Missing Reference to Active Allocated Resource
HasMemberBaseBase772Missing Release of Resource after Effective Lifetime
HasMemberVariantVariant773Missing Reference to Active File Descriptor or Handle
HasMemberVariantVariant774Allocation of File Descriptors or Handles Without Limits or Throttling
HasMemberVariantVariant775Missing Release of File Descriptor or Handle after Effective Lifetime
HasMemberVariantVariant776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
HasMemberVariantVariant777Regular Expression without Anchors
HasMemberVariantVariant780Use of RSA Algorithm without OAEP
HasMemberVariantVariant781Improper Address Validation in IOCTL with METHOD_NEITHER I/O Control Code
HasMemberVariantVariant782Exposed IOCTL with Insufficient Access Control
HasMemberVariantVariant783Operator Precedence Logic Error
HasMemberVariantVariant784Reliance on Cookies without Validation and Integrity Checking in a Security Decision
HasMemberVariantVariant785Use of Path Manipulation Function without Maximum-sized Buffer
HasMemberVariantVariant789Uncontrolled Memory Allocation
HasMemberClassClass790Improper Filtering of Special Elements
HasMemberBaseBase791Incomplete Filtering of Special Elements
HasMemberVariantVariant792Incomplete Filtering of One or More Instances of Special Elements
HasMemberVariantVariant793Only Filtering One Instance of a Special Element
HasMemberVariantVariant794Incomplete Filtering of Multiple Instances of Special Elements
HasMemberBaseBase795Only Filtering Special Elements at a Specified Location
HasMemberVariantVariant796Only Filtering Special Elements Relative to a Marker
HasMemberVariantVariant797Only Filtering Special Elements at an Absolute Position
HasMemberClassClass799Improper Control of Interaction Frequency
HasMemberBaseBase804Guessable CAPTCHA
HasMemberBaseBase805Buffer Access with Incorrect Length Value
HasMemberVariantVariant806Buffer Access Using Size of Source Buffer
HasMemberBaseBase807Reliance on Untrusted Inputs in a Security Decision
HasMemberBaseBase827Improper Control of Document Type Definition
HasMemberClassClass829Inclusion of Functionality from Untrusted Control Sphere
HasMemberBaseBase830Inclusion of Web Functionality from an Untrusted Source
HasMemberBaseBase836Use of Password Hash Instead of Password for Authentication
HasMemberBaseBase841Improper Enforcement of Behavioral Workflow
HasMemberBaseBase842Placement of User into Incorrect Group
HasMemberBaseBase843Access of Resource Using Incompatible Type ('Type Confusion')
HasMemberClassClass862Missing Authorization
HasMemberClassClass863Incorrect Authorization
HasMemberBaseBase908Use of Uninitialized Resource
HasMemberBaseBase909Missing Initialization of Resource
HasMemberBaseBase910Use of Expired File Descriptor
HasMemberBaseBase911Improper Update of Reference Count
HasMemberClassClass912Hidden Functionality
HasMemberClassClass913Improper Control of Dynamically-Managed Code Resources
HasMemberBaseBase914Improper Control of Dynamically-Identified Variables
HasMemberBaseBase915Improperly Controlled Modification of Dynamically-Determined Object Attributes
HasMemberBaseBase917Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
HasMemberBaseBase918Server-Side Request Forgery (SSRF)
HasMemberClassClass922Insecure Storage of Sensitive Information
HasMemberBaseBase939Improper Authorization in Handler for Custom URL Scheme
HasMemberBaseBase940Improper Verification of Source of a Communication Channel
HasMemberBaseBase941Incorrectly Specified Destination in a Communication Channel
HasMemberVariantVariant942Overly Permissive Cross-domain Whitelist
HasMemberClassClass943Improper Neutralization of Special Elements in Data Query Logic
HasMemberVariantVariant1004Sensitive Cookie Without 'HttpOnly' Flag
HasMemberBaseBase1007Insufficient Visual Distinction of Homoglyphs Presented to User
HasMemberBaseBase1021Improper Restriction of Rendered UI Layers or Frames
HasMemberVariantVariant1022Improper Restriction of Cross-Origin Permission to window.opener.location
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
2008-09-09CWE Content TeamMITRE
Modifications
Modification DateModifierOrganizationSource
2009-02-10CWE Content TeamMITRE
Updated the View_Filter to reflect new structure in CWE Schema v4.2
2009-03-10CWE Content TeamMITRE
updated View_Filter
2017-01-19CWE Content TeamMITRE
updated Relationships
+ View Metrics
CWEs in this viewTotal CWEs
Total619out of982
Weaknesses619out of 714
Categories0out of 237
Views0out of 31

View Components

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

CWE-36: Absolute Path Traversal

Weakness ID: 36
Abstraction: Base
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory.
+ Extended Description
This allows attackers to traverse the file system to access files or directories that are outside of the restricted directory.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity
Confidentiality
Availability

Technical Impact: Execute Unauthorized Code or Commands

The attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries.
Integrity

Technical Impact: Modify Files or Directories

The attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow an attacker to bypass authentication.
Confidentiality

Technical Impact: Read Files or Directories

The attacker may be able read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing attacks in order to break into an account on the system.
Availability

Technical Impact: DoS: Crash, Exit, or Restart

The attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the software from working at all and in the case of a protection mechanisms such as authentication, it has the potential to lockout every user of the software.
+ Demonstrative Examples

Example 1

In the example below, the path to a dictionary file is read from a system property and used to initialize a File object.

(bad)
Example Language: Java 
String filename = System.getProperty("com.domain.application.dictionaryFile");
File dictionaryFile = new File(filename);

However, the path is not validated or modified to prevent it from containing absolute path sequences before creating the File object. This allows anyone who can control the system property to determine what file is used. Ideally, the path should be resolved relative to some kind of application or user home directory.

Example 2

The following code demonstrates the unrestricted upload of a file with a Java servlet and a path traversal vulnerability. The action attribute of an HTML form is sending the upload file request to the Java servlet.

(good)
Example Language: HTML 
<form action="FileUploadServlet" method="post" enctype="multipart/form-data">

Choose a file to upload:
<input type="file" name="filename"/>
<br/>
<input type="submit" name="submit" value="Submit"/>

</form>

When submitted the Java servlet's doPost method will receive the request, extract the name of the file from the Http request header, read the file contents from the request and output the file to the local upload directory.

(bad)
Example Language: Java 
public class FileUploadServlet extends HttpServlet {
...

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String contentType = request.getContentType();

// the starting position of the boundary header
int ind = contentType.indexOf("boundary=");
String boundary = contentType.substring(ind+9);

String pLine = new String();
String uploadLocation = new String(UPLOAD_DIRECTORY_STRING); //Constant value

// verify that content type is multipart form data
if (contentType != null && contentType.indexOf("multipart/form-data") != -1) {
// extract the filename from the Http header
BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));
...
pLine = br.readLine();
String filename = pLine.substring(pLine.lastIndexOf("\\"), pLine.lastIndexOf("\""));
...

// output the file to the local upload directory
try {
BufferedWriter bw = new BufferedWriter(new FileWriter(uploadLocation+filename, true));
for (String line; (line=br.readLine())!=null; ) {
if (line.indexOf(boundary) == -1) {
bw.write(line);
bw.newLine();
bw.flush();

}

} //end of for loop
bw.close();


} catch (IOException ex) {...}
// output successful upload response HTML page

}
// output unsuccessful upload response HTML page
else
{...}

}
...

}

As with the previous example this code does not perform a check on the type of the file being uploaded. This could allow an attacker to upload any executable file or other file with malicious code.

Additionally, the creation of the BufferedWriter object is subject to relative path traversal (CWE-22, CWE-23). Depending on the executing environment, the attacker may be able to specify arbitrary files to write to, leading to a wide variety of consequences, from code execution, XSS (CWE-79), or system crash.

+ Observed Examples
ReferenceDescription
Multiple FTP clients write arbitrary files via absolute paths in server responses
ZIP file extractor allows full path
Path traversal using absolute pathname
Path traversal using absolute pathname
Path traversal using absolute pathname
Arbitrary files may be overwritten via compressed attachments that specify absolute path names for the decompressed output.
Mail client allows remote attackers to overwrite arbitrary files via an e-mail message containing a uuencoded attachment that specifies the full pathname for the file to be modified.
Remote attackers can read arbitrary files via a full pathname to the target file in config parameter.
Remote attackers can read arbitrary files via an absolute pathname.
Remote attackers can read arbitrary files by specifying the drive letter in the requested URL.
FTP server allows remote attackers to list arbitrary directories by using the "ls" command and including the drive letter name (e.g. C:) in the requested pathname.
FTP server allows remote attackers to list the contents of arbitrary drives via a ls command that includes the drive letter as an argument.
Server allows remote attackers to browse arbitrary directories via a full pathname in the arguments to certain dynamic pages.
Remote attackers can read arbitrary files via an HTTP request whose argument is a filename of the form "C:" (Drive letter), "//absolute/path", or ".." .
FTP server read/access arbitrary files using "C:\" filenames
FTP server allows a remote attacker to retrieve privileged web server system information by specifying arbitrary paths in the UNC format (\\computername\sharename).
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfViewView884CWE Cross-section
MemberOfCategoryCategory981SFP Secondary Cluster: Path Traversal
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAbsolute Path Traversal
Software Fault PatternsSFP16Path Traversal
+ References
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 9, "Filenames and Paths", Page 503.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Sean EidemillerCigital
added/updated demonstrative examples
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2008-10-14CWE Content TeamMITRE
updated Description
2010-02-16CWE Content TeamMITRE
updated Demonstrative_Examples
2010-06-21CWE Content TeamMITRE
updated Demonstrative_Examples, Description
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-09-13CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Demonstrative_Examples, Observed_Examples, References, Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-01-19CWE Content TeamMITRE
updated Related_Attack_Patterns
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms

CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data

Weakness ID: 349
Abstraction: Base
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The software, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass345Insufficient Verification of Data Authenticity
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1019Validate Inputs
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfClassClass345Insufficient Verification of Data Authenticity
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignOMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control
Integrity

Technical Impact: Bypass Protection Mechanism; Modify Application Data

An attacker could package untrusted data with trusted data to bypass protection mechanisms to gain access to and possibly modify sensitive data.
+ Observed Examples
ReferenceDescription
Does not verify that trusted entity is authoritative for all entities in its response.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERUntrusted Data Appended with Trusted Data
CERT Java Secure CodingENV01-JPlace all security-sensitive code in a single JAR and sign and seal it
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Modes_of_Introduction, Relationships
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Untrusted Data Appended with Trusted Data

CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')

Weakness ID: 843
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The program allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
+ Extended Description

When the program accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties. In languages without memory safety, such as C and C++, type confusion can lead to out-of-bounds memory access.

While this weakness is frequently associated with unions when parsing data with many different embedded object types in C, it can be present in any application that can interpret the same variable or memory location in multiple ways.

This weakness is not unique to C and C++. For example, errors in PHP applications can be triggered by providing array parameters when scalars are expected, or vice versa. Languages such as Perl, which perform automatic conversion of a variable of one type when it is accessed as if it were another type, can also contain these issues.

+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfClassClass704Incorrect Type Conversion or Cast
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C: (Undetermined Prevalence)

C++: (Undetermined Prevalence)

+ Alternate Terms
Object Type Confusion
+ Demonstrative Examples

Example 1

The following code uses a union to support the representation of different types of messages. It formats messages differently, depending on their type.

(bad)
Example Language:
#define NAME_TYPE 1
#define ID_TYPE 2

struct MessageBuffer
{
int msgType;
union {
char *name;
int nameID;

};

};


int main (int argc, char **argv) {
struct MessageBuffer buf;
char *defaultMessage = "Hello World";

buf.msgType = NAME_TYPE;
buf.name = defaultMessage;
printf("Pointer of buf.name is %p\n", buf.name);
/* This particular value for nameID is used to make the code architecture-independent. If coming from untrusted input, it could be any value. */

buf.nameID = (int)(defaultMessage + 1);
printf("Pointer of buf.name is now %p\n", buf.name);
if (buf.msgType == NAME_TYPE) {
printf("Message: %s\n", buf.name);

}
else {
printf("Message: Use ID %d\n", buf.nameID);

}

}

The code intends to process the message as a NAME_TYPE, and sets the default message to "Hello World." However, since both buf.name and buf.nameID are part of the same union, they can act as aliases for the same memory location, depending on memory layout after compilation.

As a result, modification of buf.nameID - an int - can effectively modify the pointer that is stored in buf.name - a string.

Execution of the program might generate output such as:

Pointer of name is 10830
Pointer of name is now 10831
Message: ello World

Notice how the pointer for buf.name was changed, even though buf.name was not explicitly modified.

In this case, the first "H" character of the message is omitted. However, if an attacker is able to fully control the value of buf.nameID, then buf.name could contain an arbitrary pointer, leading to out-of-bounds reads or writes.

Example 2

The following PHP code accepts a value, adds 5, and prints the sum.

(bad)
Example Language: PHP 
$value = $_GET['value'];
$sum = $value + 5;
echo "value parameter is '$value'<p>";
echo "SUM is $sum";

When called with the following query string:

value=123

the program calculates the sum and prints out:

SUM is 128

However, the attacker could supply a query string such as:

value[]=123

The "[]" array syntax causes $value to be treated as an array type, which then generates a fatal error when calculating $sum:

Fatal error: Unsupported operand types in program.php on line 2

Example 3

The following Perl code is intended to look up the privileges for user ID's between 0 and 3, by performing an access of the $UserPrivilegeArray reference. It is expected that only userID 3 is an admin (since this is listed in the third element of the array).

(bad)
Example Language: Perl 
my $UserPrivilegeArray = ["user", "user", "admin", "user"];

my $userID = get_current_user_ID();

if ($UserPrivilegeArray eq "user") {
print "Regular user!\n";

}
else {
print "Admin!\n";

}

print "\$UserPrivilegeArray = $UserPrivilegeArray\n";

In this case, the programmer intended to use "$UserPrivilegeArray->{$userID}" to access the proper position in the array. But because the subscript was omitted, the "user" string was compared to the scalar representation of the $UserPrivilegeArray reference, which might be of the form "ARRAY(0x229e8)" or similar.

Since the logic also "fails open" (CWE-636), the result of this bug is that all users are assigned administrator privileges.

While this is a forced example, it demonstrates how type confusion can have security consequences, even in memory-safe languages.

+ Observed Examples
ReferenceDescription
Type confusion in CSS sequence leads to out-of-bounds read.
Size inconsistency allows code execution, first discovered when it was actively exploited in-the-wild.
Improperly-parsed file containing records of different types leads to code execution when a memory location is interpreted as a different object than intended.
+ Notes

Applicable Platform

This weakness is possible in any type-unsafe programming language.

Research Gap

Type confusion weaknesses have received some attention by applied researchers and major software vendors for C and C++ code. Some publicly-reported vulnerabilities probably have type confusion as a root-cause weakness, but these may be described as "memory corruption" instead. This weakness seems likely to gain prominence in upcoming years.

For other languages, there are very few public reports of type confusion weaknesses. These are probably under-studied. Since many programs rely directly or indirectly on loose typing, a potential "type confusion" behavior might be intentional, possibly requiring more manual analysis.

+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CERT C Secure CodingEXP39-CExactDo not access a variable through a pointer of an incompatible type
+ References
[REF-811] Mark Dowd, Ryan Smith and David Dewey. "Attacking Interoperability". "Type Confusion Vulnerabilities," page 59. 2009. <http://www.azimuthsecurity.com/resources/bh2009_dowd_smith_dewey.pdf>.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Type Confusion", Page 319.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
2011-05-15CWE Content TeamMITRE
Modifications
Modification DateModifierOrganizationSource
2012-05-11CWE Content TeamMITRE
updated References
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Taxonomy_Mappings

CWE-767: Access to Critical Private Variable via Public Method

Weakness ID: 767
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software defines a public method that reads or modifies a private variable.
+ Extended Description
If an attacker modifies the variable to contain unexpected values, this could violate assumptions from other parts of the code. Additionally, if an attacker can read the private variable, it may expose sensitive information or make it easier to launch further attacks.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass668Exposure of Resource to Wrong Sphere
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory265Privilege / Sandbox Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C++: (Undetermined Prevalence)

C#: (Undetermined Prevalence)

Java: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity
Other

Technical Impact: Modify Application Data; Other

+ Demonstrative Examples

Example 1

The following example declares a critical variable to be private, and then allows the variable to be modified by public methods.

(bad)
Example Language: C++ 
private: float price;
public: void changePrice(float newPrice) {
price = newPrice;

}

Example 2

The following example could be used to implement a user forum where a single user (UID) can switch between multiple profiles (PID).

(bad)
Example Language: Java 
public class Client {
private int UID;
public int PID;
private String userName;
public Client(String userName){
PID = getDefaultProfileID();
UID = mapUserNametoUID( userName );
this.userName = userName;

}
public void setPID(int ID) {
UID = ID;

}

}

The programmer implemented setPID with the intention of modifying the PID variable, but due to a typo. accidentally specified the critical variable UID instead. If the program allows profile IDs to be between 1 and 10, but a UID of 1 means the user is treated as an admin, then a user could gain administrative privileges as a result of this typo.

+ Potential Mitigations

Phase: Implementation

Use class accessor and mutator methods appropriately. Perform validation when accepting data from a public method that is intended to modify a critical private variable. Also be sure that appropriate access controls are being applied when a public method interfaces with critical data.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory963SFP Secondary Cluster: Exposed Data
+ Notes

Maintenance

This entry is closely associated with access control for public methods. If the public methods are restricted with proper access controls, then the information in the private variable will not be exposed to unexpected parties. There may be chaining or composite relationships between improper access controls and this weakness.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CLASPFailure to protect stored data from modification
Software Fault PatternsSFP23Exposed Data
CERT Perl Secure CodingOOP31-PLImpreciseDo not access private variables or subroutines in other packages
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
2009-03-03CWE Content TeamMITRE
Modifications
Modification DateModifierOrganizationSource
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Likelihood_of_Exploit, Relationships, Taxonomy_Mappings

CWE-464: Addition of Data Structure Sentinel

Weakness ID: 464
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The accidental addition of a data-structure sentinel can cause serious programming logic problems.
+ Extended Description
Data-structure sentinels are often used to mark the structure of data. A common example of this is the null character at the end of strings or a special sentinel to mark the end of a linked list. It is dangerous to allow this type of control data to be easily accessible. Therefore, it is important to protect from the addition or modification of sentinels.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory461Data Structure Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C: (Undetermined Prevalence)

C++: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity

Technical Impact: Modify Application Data

Generally this error will cause the data structure to not work properly by truncating the data.
+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

The following example assigns some character values to a list of characters and prints them each individually, and then as a string. The third character value is intended to be an integer taken from user input and converted to an int.

(bad)
Example Language:
char *foo;
foo=malloc(sizeof(char)*5);
foo[0]='a';
foo[1]='a';
foo[2]=atoi(getc(stdin));
foo[3]='c';
foo[4]='\0'
printf("%c %c %c %c %c \n",foo[0],foo[1],foo[2],foo[3],foo[4]);
printf("%s\n",foo);

The first print statement will print each character separated by a space. However, if a non-integer is read from stdin by getc, then atoi will not make a conversion and return 0. When foo is printed as a string, the 0 at character foo[2] will act as a NULL terminator and foo[3] will never be printed.

+ Potential Mitigations

Phases: Implementation; Architecture and Design

Encapsulate the user from interacting with data sentinels. Validate user input to verify that sentinels are not present.

Phase: Implementation

Proper error checking can reduce the risk of inadvertently introducing sentinel values into data. For example, if a parsing function fails or encounters an error, it might return a value that is the same as the sentinel.

Phase: Architecture and Design

Use an abstraction library to abstract away risky APIs. This is not a complete solution.

Phase: Operation

Use OS-level preventative functionality. This is not a complete solution.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CLASPAddition of data-structure sentinel
CERT C Secure CodingSTR03-CDo not inadvertently truncate a null-terminated byte string
CERT C Secure CodingSTR06-CDo not assume that strtok() leaves the parse string unchanged
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
CLASP
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Applicable_Platforms, Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2009-07-27CWE Content TeamMITRE
updated Demonstrative_Examples, Description, Other_Notes, Potential_Mitigations, Relationships
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2011-09-13CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples, Likelihood_of_Exploit, Taxonomy_Mappings
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Addition of Data-structure Sentinel

CWE-407: Algorithmic Complexity

Weakness ID: 407
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Availability

Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)

The typical consequence is CPU consumption, but memory consumption and consumption of other resources can also occur.
+ Likelihood Of Exploit
Low
+ Observed Examples
ReferenceDescription
CPU consumption via inputs that cause many hash table collisions.
CPU consumption via inputs that cause many hash table collisions.
Product performs unnecessary processing before dropping an invalid packet.
CPU and memory consumption using many wildcards.
Product allows attackers to cause multiple copies of a program to be loaded more quickly than the program can detect that other copies are running, then exit. This type of error should probably have its own category, where teardown takes more time than initialization.
Network monitoring system allows remote attackers to cause a denial of service (CPU consumption and detection outage) via crafted network traffic, aka a "backtracking attack."
Wiki allows remote attackers to cause a denial of service (CPU consumption) by performing a diff between large, crafted pages that trigger the worst case algorithmic complexity.
Wiki allows remote attackers to cause a denial of service (CPU consumption) by performing a diff between large, crafted pages that trigger the worst case algorithmic complexity.
OS allows attackers to cause a denial of service (CPU consumption) via crafted Gregorian dates.
Memory leak by performing actions faster than the software can clear them.
+ Functional Areas
  • Cryptography
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfViewView884CWE Cross-section
MemberOfCategoryCategory977SFP Secondary Cluster: Design
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAlgorithmic Complexity
+ References
[REF-395] Crosby and Wallach. "Algorithmic Complexity Attacks". <http://www.cs.rice.edu/~scrosby/hash/CrosbyWallach_UsenixSec2003/index.html>.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2009-07-27CWE Content TeamMITRE
updated Functional_Areas, Other_Notes
2009-10-29CWE Content TeamMITRE
updated Common_Consequences
2009-12-28CWE Content TeamMITRE
updated Applicable_Platforms, Likelihood_of_Exploit
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Observed_Examples, Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships
2015-12-07CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Likelihood_of_Exploit

CWE-774: Allocation of File Descriptors or Handles Without Limits or Throttling

Weakness ID: 774
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software allocates file descriptors or handles on behalf of an actor without imposing any restrictions on how many descriptors can be allocated, in violation of the intended security policy for that actor.
+ Extended Description
This can cause the software to consume all available file descriptors or handles, which can prevent other processes from performing critical file processing operations.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
NatureTypeIDName
ChildOfBaseBase769Uncontrolled File Descriptor Consumption
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfBaseBase769Uncontrolled File Descriptor Consumption
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Availability

Technical Impact: DoS: Resource Consumption (Other)

When allocating resources without limits, an attacker could prevent all other processes from accessing the same type of resource.
+ Likelihood Of Exploit
Low
+ Potential Mitigations

Phases: Operation; Architecture and Design

Strategy: Resource Limitation

Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems. When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users. Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory985SFP Secondary Cluster: Unrestricted Consumption
+ Notes

Theoretical

Vulnerability theory is largely about how behaviors and resources interact. "Resource exhaustion" can be regarded as either a consequence or an attack, depending on the perspective. This entry is an attempt to reflect one of the underlying weaknesses that enable these attacks (or consequences) to take place.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
Software Fault PatternsSFP13Unrestricted Consumption
+ References
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 10, "Resource Limits", Page 574.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
2009-05-13CWE Content TeamMITRE
Modifications
Modification DateModifierOrganizationSource
2010-04-05CWE Content TeamMITRE
updated Potential_Mitigations
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated References, Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2015-12-07CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Likelihood_of_Exploit, Relationships

CWE-770: Allocation of Resources Without Limits or Throttling

Weakness ID: 770
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on how many resources can be allocated, in violation of the intended security policy for that actor.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1011Authorize Actors
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignOMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Implementation
Operation
System Configuration
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Availability

Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)

When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource.
+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

This code allocates a socket and forks each time it receives a new connection.

(bad)
Example Language:
sock=socket(AF_INET, SOCK_STREAM, 0);
while (1) {
newsock=accept(sock, ...);
printf("A connection has been accepted\n");
pid = fork();

}

The program does not track how many connections have been made, and it does not limit the number of connections. Because forking is a relatively expensive operation, an attacker would be able to cause the system to run out of CPU, processes, or memory by making a large number of connections. Alternatively, an attacker could consume all available connections, preventing others from accessing the system remotely.

Example 2

In the following example a server socket connection is used to accept a request to store data on the local file system using a specified filename. The method openSocketConnection establishes a server socket to accept requests from a client. When a client establishes a connection to this service the getNextMessage method is first used to retrieve from the socket the name of the file to store the data, the openFileToWrite method will validate the filename and open a file to write to on the local file system. The getNextMessage is then used within a while loop to continuously read data from the socket and output the data to the file until there is no longer any data from the socket.

(bad)
Example Language:
int writeDataFromSocketToFile(char *host, int port)
{

char filename[FILENAME_SIZE];
char buffer[BUFFER_SIZE];
int socket = openSocketConnection(host, port);

if (socket < 0) {
printf("Unable to open socket connection");
return(FAIL);

}
if (getNextMessage(socket, filename, FILENAME_SIZE) > 0) {
if (openFileToWrite(filename) > 0) {
while (getNextMessage(socket, buffer, BUFFER_SIZE) > 0){
if (!(writeToFile(buffer) > 0))
break;

}

}
closeFile();

}
closeSocket(socket);

}

This example creates a situation where data can be dumped to a file on the local file system without any limits on the size of the file. This could potentially exhaust file or disk resources and/or limit other clients' ability to access the service.

Example 3

In the following example, the processMessage method receives a two dimensional character array containing the message to be processed. The two-dimensional character array contains the length of the message in the first character array and the message body in the second character array. The getMessageLength method retrieves the integer value of the length from the first character array. After validating that the message length is greater than zero, the body character array pointer points to the start of the second character array of the two-dimensional character array and memory is allocated for the new body character array.

(bad)
Example Language:
/* process message accepts a two-dimensional character array of the form [length][body] containing the message to be processed */
int processMessage(char **message)
{
char *body;

int length = getMessageLength(message[0]);

if (length > 0) {
body = &message[1][0];
processMessageBody(body);
return(SUCCESS);

}
else {
printf("Unable to process message; invalid message length");
return(FAIL);

}

}

This example creates a situation where the length of the body character array can be very large and will consume excessive memory, exhausting system resources. This can be avoided by restricting the length of the second character array with a maximum length check

Also, consider changing the type from 'int' to 'unsigned int', so that you are always guaranteed that the number is positive. This might not be possible if the protocol specifically requires allowing negative values, or if you cannot control the return value from getMessageLength(), but it could simplify the check to ensure the input is positive, and eliminate other errors such as signed-to-unsigned conversion errors (CWE-195) that may occur elsewhere in the code.

(good)
Example Language:
unsigned int length = getMessageLength(message[0]);
if ((length > 0) && (length < MAX_LENGTH)) {...}

Example 4

In the following example, a server object creates a server socket and accepts client connections to the socket. For every client connection to the socket a separate thread object is generated using the ClientSocketThread class that handles request made by the client through the socket.

(bad)
Example Language: Java 
public void acceptConnections() {
try {
ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
int counter = 0;
boolean hasConnections = true;
while (hasConnections) {
Socket client = serverSocket.accept();
Thread t = new Thread(new ClientSocketThread(client));
t.setName(client.getInetAddress().getHostName() + ":" + counter++);
t.start();

}
serverSocket.close();


} catch (IOException ex) {...}

}

In this example there is no limit to the number of client connections and client threads that are created. Allowing an unlimited number of client connections and threads could potentially overwhelm the system and system resources.

The server should limit the number of client connections and the client threads that are created. This can be easily done by creating a thread pool object that limits the number of threads that are generated.

(good)
Example Language: Java 
public static final int SERVER_PORT = 4444;
public static final int MAX_CONNECTIONS = 10;
...

public void acceptConnections() {
try {
ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
int counter = 0;
boolean hasConnections = true;
while (hasConnections) {
hasConnections = checkForMoreConnections();
Socket client = serverSocket.accept();
Thread t = new Thread(new ClientSocketThread(client));
t.setName(client.getInetAddress().getHostName() + ":" + counter++);
ExecutorService pool = Executors.newFixedThreadPool(MAX_CONNECTIONS);
pool.execute(t);

}
serverSocket.close();


} catch (IOException ex) {...}

}

Example 5

An unnamed web site allowed a user to purchase tickets for an event. A menu option allowed the user to purchase up to 10 tickets, but the back end did not restrict the actual number of tickets that could be purchased.

Example 5 References:

[REF-667] Rafal Los. "Real-Life Example of a 'Business Logic Defect' (Screen Shots!)". 2011. <http://h30501.www3.hp.com/t5/Following-the-White-Rabbit-A/Real-Life-Example-of-a-Business-Logic-Defect-Screen-Shots/ba-p/22581>.
+ Observed Examples
ReferenceDescription
Language interpreter does not restrict the number of temporary files being created when handling a MIME request with a large number of parts..
Driver does not use a maximum width when invoking sscanf style functions, causing stack consumption.
Large integer value for a length property in an object causes a large amount of memory allocation.
Product allows exhaustion of file descriptors when processing a large number of TCP packets.
Communication product allows memory consumption with a large number of SIP requests, which cause many sessions to be created.
Product allows attackers to cause a denial of service via a large number of directives, each of which opens a separate window.
CMS does not restrict the number of searches that can occur simultaneously, leading to resource exhaustion.
+ Potential Mitigations

Phase: Requirements

Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.

Phase: Architecture and Design

Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.

Phase: Architecture and Design

Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place, and it will help the administrator to identify who is committing the abuse. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.

Phase: Implementation

Strategy: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a whitelist of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs (i.e., do not rely on a blacklist). A blacklist is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, blacklists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
This will only be applicable to cases where user input can influence the size or frequency of resource allocations.

Phase: Architecture and Design

For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Phase: Architecture and Design

Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, typically by using increasing time delays uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution can be difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.

Phase: Architecture and Design

Ensure that protocols have specific limits of scale placed on them.

Phases: Architecture and Design; Implementation

If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery. Ensure that all failures in resource allocation place the system into a safe posture.

Phases: Operation; Architecture and Design

Strategy: Resource Limitation

Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems. When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users. Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).
+ Detection Methods

Manual Static Analysis

Manual static analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. If denial-of-service is not considered a significant risk, or if there is strong emphasis on consequences such as code execution, then manual analysis may not focus on this weakness at all.

Fuzzing

While fuzzing is typically geared toward finding low-level implementation bugs, it can inadvertently find uncontrolled resource allocation problems. This can occur when the fuzzer generates a large number of test cases but does not restart the targeted software in between test cases. If an individual test case produces a crash, but it does not do so reliably, then an inability to limit resource allocation may be the cause.

When the allocation is directly affected by numeric inputs, then fuzzing may produce indications of this weakness.

Effectiveness: Opportunistic

Automated Dynamic Analysis

Certain automated dynamic analysis techniques may be effective in producing side effects of uncontrolled resource allocation problems, especially with resources such as processes, memory, and connections. The technique may involve generating a large number of requests to the software within a short time frame. Manual analysis is likely required to interpret the results.

Automated Static Analysis

Specialized configuration or tuning may be required to train automated tools to recognize this weakness.

Automated static analysis typically has limited utility in recognizing unlimited allocation problems, except for the missing release of program-independent system resources such as files, sockets, and processes, or unchecked arguments to memory. For system resources, automated static analysis may be able to detect circumstances in which resources are not released after they have expired, or if too much of a resource is requested at once, as can occur with memory. Automated analysis of configuration files may be able to detect settings that do not specify a maximum value.

Automated static analysis tools will not be appropriate for detecting exhaustion of custom resources, such as an intended security policy in which a bulletin board user is only allowed to make a limited number of posts per day.

+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Notes

Maintenance

"Resource exhaustion" (CWE-400) is currently treated as a weakness, although it is more like a category of weaknesses that all have the same type of consequence. While this entry treats CWE-400 as a parent in view 1000, the relationship is probably more appropriately described as a chain.

Theoretical

Vulnerability theory is largely about how behaviors and resources interact. "Resource exhaustion" can be regarded as either a consequence or an attack, depending on the perspective. This entry is an attempt to reflect one of the underlying weaknesses that enable these attacks (or consequences) to take place.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CERT Java Secure CodingFIO04-JClose resources when they are no longer needed
CERT Java Secure CodingSER12-JAvoid memory and resource leaks during serialization
CERT Java Secure CodingMSC05-JDo not exhaust heap space
+ References
[REF-386] Joao Antunes, Nuno Ferreira Neves and Paulo Verissimo. "Detection and Prediction of Resource-Exhaustion Vulnerabilities". Proceedings of the IEEE International Symposium on Software Reliability Engineering (ISSRE). 2008-11. <http://homepages.di.fc.ul.pt/~nuno/PAPERS/ISSRE08.pdf>.
[REF-387] D.J. Bernstein. "Resource exhaustion". <http://cr.yp.to/docs/resources.html>.
[REF-388] Pascal Meunier. "Resource exhaustion". Secure Programming Educational Material. 2004. <http://homes.cerias.purdue.edu/~pmeunier/secprog/sanitized/class1/6.resource%20exhaustion.ppt>.
[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 17, "Protecting Against Denial of Service Attacks" Page 517. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoft.com/mspress/books/toc/5957.aspx>.
[REF-672] Frank Kim. "Top 25 Series - Rank 22 - Allocation of Resources Without Limits or Throttling". SANS Software Security Institute. 2010-03-23. <http://blogs.sans.org/appsecstreetfighter/2010/03/23/top-25-series-rank-22-allocation-of-resources-without-limits-or-throttling/>.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 10, "Resource Limits", Page 574.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
2009-05-13CWE Content TeamMITRE
Modifications
Modification DateModifierOrganizationSource
2009-07-27CWE Content TeamMITRE
updated Related_Attack_Patterns
2009-10-29CWE Content TeamMITRE
updated Relationships
2009-12-28CWE Content TeamMITRE
updated Applicable_Platforms, Demonstrative_Examples, Detection_Factors, Observed_Examples, References, Time_of_Introduction
2010-02-16CWE Content TeamMITRE
updated Common_Consequences, Detection_Factors, Potential_Mitigations, References, Related_Attack_Patterns, Relationships
2010-04-05CWE Content TeamMITRE
updated Common_Consequences, Demonstrative_Examples, Related_Attack_Patterns
2010-06-21CWE Content TeamMITRE
updated Common_Consequences, Potential_Mitigations, References
2010-09-27CWE Content TeamMITRE
updated Demonstrative_Examples, Potential_Mitigations
2011-03-29CWE Content TeamMITRE
updated Demonstrative_Examples, Detection_Factors, Relationships
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27CWE Content TeamMITRE
updated Relationships
2011-09-13CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Demonstrative_Examples, References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-02-18CWE Content TeamMITRE
updated Related_Attack_Patterns
2014-06-23CWE Content TeamMITRE
updated Related_Attack_Patterns
2014-07-30CWE Content TeamMITRE
updated Relationships
2015-12-07CWE Content TeamMITRE
updated Related_Attack_Patterns
2017-05-03CWE Content TeamMITRE
updated Related_Attack_Patterns
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples, Likelihood_of_Exploit, Modes_of_Introduction, Potential_Mitigations, References, Relationships, Taxonomy_Mappings

CWE-670: Always-Incorrect Control Flow Implementation

Weakness ID: 670
Abstraction: Class
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated.
+ Extended Description
This weakness captures cases in which a particular code segment is always incorrect with respect to the algorithm that it is implementing. For example, if a C programmer intends to include multiple statements in a single block but does not include the enclosing braces (CWE-483), then the logic is always incorrect. This issue is in contrast to most weaknesses in which the code usually behaves correctly, except when it is externally manipulated in malicious ways.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory438Behavioral Problems
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
ImplementationThis issue typically appears in rarely-tested code, since the "always-incorrect" nature will be detected as a bug during normal usage.
Operation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Other

Technical Impact: Other; Alter Execution Logic

+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory977SFP Secondary Cluster: Design
+ Notes

Maintenance

This node could possibly be split into lower-level nodes. "Early Return" is for returning control to the caller too soon (e.g., CWE-584). "Excess Return" is when control is returned too far up the call stack (CWE-600, CWE-395). "Improper control limitation" occurs when the product maintains control at a lower level of execution, when control should be returned "further" up the call stack (CWE-455). "Incorrect syntax" covers code that's "just plain wrong" such as CWE-484 and CWE-483.
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Relationships, Other_Notes
2009-07-27CWE Content TeamMITRE
updated Maintenance_Notes, Modes_of_Introduction, Other_Notes, Relationships
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-01-19CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Relationships

CWE-88: Argument Injection or Modification

Weakness ID: 88
Abstraction: Base
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The software does not sufficiently delimit the arguments being passed to a component in another control sphere, allowing alternate arguments to be provided, leading to potentially security-relevant changes.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1019Validate Inputs
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
ImplementationREALIZATION: This weakness is caused during implementation of an architectural security tactic.
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Confidentiality
Integrity
Availability
Other

Technical Impact: Execute Unauthorized Code or Commands; Alter Execution Logic; Read Application Data; Modify Application Data

An attacker could include arguments that allow unintended commands or code to be executed, allow sensitive data to be read or modified or could cause other unintended behavior.
+ Demonstrative Examples

Example 1

The following simple program accepts a filename as a command line argument and displays the contents of the file back to the user. The program is installed setuid root because it is intended for use as a learning tool to allow system administrators in-training to inspect privileged system files without giving them the ability to modify them or damage the system.

(bad)
Example Language:
int main(int argc, char** argv) {
char cmd[CMD_MAX] = "/usr/bin/cat ";
strcat(cmd, argv[1]);
system(cmd);

}

Because the program runs with root privileges, the call to system() also executes with root privileges. If a user specifies a standard filename, the call works as expected. However, if an attacker passes a string of the form ";rm -rf /", then the call to system() fails to execute cat due to a lack of arguments and then plows on to recursively delete the contents of the root partition.

Note that if argv[1] is a very long argument, then this issue might also be subject to a buffer overflow (CWE-120).

+ Observed Examples
ReferenceDescription
Canonical Example
Web browser executes Telnet sessions using command line arguments that are specified by the web site, which could allow remote attackers to execute arbitrary commands.
Web browser allows remote attackers to execute commands by spawning Telnet with a log file option on the command line and writing arbitrary code into an executable file which is later executed.
Argument injection vulnerability in the mail function for PHP may allow attackers to bypass safe mode restrictions and modify command line arguments to the MTA (e.g. sendmail) possibly executing commands.
Help and Support center in windows does not properly validate HCP URLs, which allows remote attackers to execute arbitrary code via quotation marks in an "hcp://" URL.
Mail client does not sufficiently filter parameters of mailto: URLs when using them as arguments to mail executable, which allows remote attackers to execute arbitrary programs.
Web browser doesn't filter "-" when invoking various commands, allowing command-line switches to be specified.
Mail client allows remote attackers to execute arbitrary code via a URI that uses a UNC network share pathname to provide an alternate configuration file.
SSH URI handler for web browser allows remote attackers to execute arbitrary code or conduct port forwarding via the a command line option.
Web browser doesn't filter "-" when invoking various commands, allowing command-line switches to be specified.
Argument injection vulnerability in TellMe 1.2 and earlier allows remote attackers to modify command line arguments for the Whois program and obtain sensitive information via "--" style options in the q_Host parameter.
Beagle before 0.2.5 can produce certain insecure command lines to launch external helper applications while indexing, which allows attackers to execute arbitrary commands. NOTE: it is not immediately clear whether this issue involves argument injection, shell metacharacters, or other issues.
Argument injection vulnerability in Internet Explorer 6 for Windows XP SP2 allows user-assisted remote attackers to modify command line arguments to an invoked mail client via " (double quote) characters in a mailto: scheme handler, as demonstrated by launching Microsoft Outlook with an arbitrary filename as an attachment. NOTE: it is not clear whether this issue is implementation-specific or a problem in the Microsoft API.
Argument injection vulnerability in Mozilla Firefox 1.0.6 allows user-assisted remote attackers to modify command line arguments to an invoked mail client via " (double quote) characters in a mailto: scheme handler, as demonstrated by launching Microsoft Outlook with an arbitrary filename as an attachment. NOTE: it is not clear whether this issue is implementation-specific or a problem in the Microsoft API.
Argument injection vulnerability in Avant Browser 10.1 Build 17 allows user-assisted remote attackers to modify command line arguments to an invoked mail client via " (double quote) characters in a mailto: scheme handler, as demonstrated by launching Microsoft Outlook with an arbitrary filename as an attachment. NOTE: it is not clear whether this issue is implementation-specific or a problem in the Microsoft API.
Argument injection vulnerability in the URI handler in Skype 2.0.*.104 and 2.5.*.0 through 2.5.*.78 for Windows allows remote authorized attackers to download arbitrary files via a URL that contains certain command-line switches.
Argument injection vulnerability in WinSCP 3.8.1 build 328 allows remote attackers to upload or download arbitrary files via encoded spaces and double-quote characters in a scp or sftp URI.
Argument injection vulnerability in the Windows Object Packager (packager.exe) in Microsoft Windows XP SP1 and SP2 and Server 2003 SP1 and earlier allows remote user-assisted attackers to execute arbitrary commands via a crafted file with a "/" (slash) character in the filename of the Command Line property, followed by a valid file extension, which causes the command before the slash to be executed, aka "Object Packager Dialogue Spoofing Vulnerability."
Argument injection vulnerability in HyperAccess 8.4 allows user-assisted remote attackers to execute arbitrary vbscript and commands via the /r option in a telnet:// URI, which is configured to use hawin32.exe.
Argument injection vulnerability in the telnet daemon (in.telnetd) in Solaris 10 and 11 (SunOS 5.10 and 5.11) misinterprets certain client "-f" sequences as valid requests for the login program to skip authentication, which allows remote attackers to log into certain accounts, as demonstrated by the bin account.
Language interpreter's mail function accepts another argument that is concatenated to a string used in a dangerous popen() call. Since there is no neutralization of this argument, both OS Command Injection (CWE-78) and Argument Injection (CWE-88) are possible.
+ Potential Mitigations

Phase: Architecture and Design

Strategy: Input Validation

Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, request headers as well as content, URL components, e-mail, files, databases, and any external systems that provide data to the application. Perform input validation at well-defined interfaces.

Phase: Implementation

Strategy: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a whitelist of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs (i.e., do not rely on a blacklist). A blacklist is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, blacklists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Phase: Implementation

Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.

Phase: Implementation

Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180, CWE-181). Make sure that your application does not inadvertently decode the same input twice (CWE-174). Such errors could be used to bypass whitelist schemes by introducing dangerous inputs after they have been checked. Use libraries such as the OWASP ESAPI Canonicalization control. Consider performing repeated canonicalization until your input does not change any more. This will avoid double-decoding and similar scenarios, but it might inadvertently modify inputs that are allowed to contain properly-encoded dangerous content.

Phase: Implementation

When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.

Phase: Implementation

When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.

Phase: Testing

Use automated static analysis tools that target this type of weakness. Many modern techniques use data flow analysis to minimize the number of false positives. This is not a perfect solution, since 100% accuracy and coverage are not feasible.

Phase: Testing

Use dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
+ Weakness Ordinalities
OrdinalityDescription
Primary
(where the weakness exists independent of other weaknesses)
+ Affected Resources
  • System Process
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Notes

Relationship

At one layer of abstraction, this can overlap other weaknesses that have whitespace problems, e.g. injection of javascript into attributes of HTML tags.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERArgument Injection or Modification
CERT C Secure CodingENV03-CSanitize the environment when invoking external programs
CERT C Secure CodingENV33-CImpreciseDo not call system()
CERT C Secure CodingSTR02-CSanitize data passed to complex subsystems
WASC30Mail Command Injection
+ References
[REF-859] Steven Christey. "Argument injection issues". <http://www.securityfocus.com/archive/1/archive/1/460089/100/100/threaded>.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 10, "The Argument Array", Page 567.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2008-11-24CWE Content TeamMITRE
updated Observed_Examples, Relationships, Taxonomy_Mappings
2009-07-27CWE Content TeamMITRE
updated Other_Notes, Relationship_Notes
2009-10-29CWE Content TeamMITRE
updated Observed_Examples
2010-02-16CWE Content TeamMITRE
updated Potential_Mitigations, Relationships, Taxonomy_Mappings
2010-04-05CWE Content TeamMITRE
updated Related_Attack_Patterns
2010-06-21CWE Content TeamMITRE
updated Observed_Examples, Relationships
2010-09-27CWE Content TeamMITRE
updated Relationships
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-09-13CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Demonstrative_Examples, Observed_Examples, References, Related_Attack_Patterns, Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-06-23CWE Content TeamMITRE
updated Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships
2015-12-07CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Causal_Nature, Modes_of_Introduction, Relationships, Taxonomy_Mappings

CWE-582: Array Declared Public, Final, and Static

Weakness ID: 582
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The program declares an array public, final, and static, which is not sufficient to prevent the array's contents from being modified.
+ Extended Description
Because arrays are mutable objects, the final constraint requires that the array object itself be assigned only once, but makes no guarantees about the values of the array elements. Since the array is public, a malicious program can change the values stored in the array. As such, in most cases an array declared public, final and static is a bug.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass668Exposure of Resource to Wrong Sphere
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory490Mobile Code Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

Java: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity

Technical Impact: Modify Application Data

+ Demonstrative Examples

Example 1

The following Java Applet code mistakenly declares an array public, final and static.

(bad)
Example Language: Java 
public final class urlTool extends Applet {
public final static URL[] urls;
...

}
+ Potential Mitigations

Phase: Implementation

In most situations the array should be made private.
+ Weakness Ordinalities
OrdinalityDescription
Primary
(where the weakness exists independent of other weaknesses)
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CERT Java Secure CodingOBJ10-JDo not use public static nonfinal variables
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Relationships, Other_Notes, Weakness_Ordinalities
2008-10-14CWE Content TeamMITRE
updated Background_Details, Demonstrative_Examples, Description, Other_Notes
2009-05-27CWE Content TeamMITRE
updated Demonstrative_Examples
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Mobile Code: Unsafe Array Declaration

CWE-11: ASP.NET Misconfiguration: Creating Debug Binary

Weakness ID: 11
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
Debugging messages help attackers learn about the system and plan a form of attack.
+ Extended Description
ASP .NET applications can be configured to produce debug binaries. These binaries give detailed debugging messages and should not be used in production environments. Debug binaries are meant to be used in a development or testing environment and can pose a security risk if they are deployed to production.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfVariantVariant215Information Exposure Through Debug Information
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory519.NET Environment Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
Operation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

ASP.NET: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Confidentiality

Technical Impact: Read Application Data

Attackers can leverage the additional information they gain from debugging output to mount attacks targeted on the framework, database, or other resources used by the application.
+ Demonstrative Examples

Example 1

The file web.config contains the debug mode setting. Setting debug to "true" will let the browser display debugging information.

(bad)
Example Language: XML 
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.web>
<compilation
defaultLanguage="c#"
debug="true"
/>
...

</system.web>

</configuration>

Change the debug mode to false when the application is deployed into production.

+ Potential Mitigations

Phase: System Configuration

Avoid releasing debug binaries into the production environment. Change the debug mode to false when the application is deployed into production.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory27PK - Environment
MemberOfCategoryCategory963SFP Secondary Cluster: Exposed Data
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
7 Pernicious KingdomsASP.NET Misconfiguration: Creating Debug Binary
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
7 Pernicious Kingdoms
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Demonstrative_Example, Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Description, Other_Notes
2009-07-27CWE Content TeamMITRE
updated Background_Details, Common_Consequences, Demonstrative_Examples, Description, Other_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2013-02-21CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Relationships

CWE-12: ASP.NET Misconfiguration: Missing Custom Error Page

Weakness ID: 12
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
An ASP .NET application must enable custom error pages in order to prevent attackers from mining information from the framework's built-in responses.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass756Missing Custom Error Page
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory519.NET Environment Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
Operation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

ASP.NET: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Confidentiality

Technical Impact: Read Application Data

Default error pages gives detailed information about the error that occurred, and should not be used in production environments. Attackers can leverage the additional information provided by a default error page to mount attacks targeted on the framework, database, or other resources used by the application.
+ Demonstrative Examples

Example 1

The mode attribute of the <customErrors> tag in the Web.config file defines whether custom or default error pages are used.

In the following insecure ASP.NET application setting, custom error message mode is turned off. An ASP.NET error message with detailed stack trace and platform versions will be returned.

(bad)
Example Language: ASP.NET 
<customErrors mode="Off" />

A more secure setting is to set the custom error message mode for remote users only. No defaultRedirect error page is specified. The local user on the web server will see a detailed stack trace. For remote users, an ASP.NET error message with the server customError configuration setting and the platform version will be returned.

(good)
Example Language: ASP.NET 
<customErrors mode="RemoteOnly" />

Another secure option is to set the mode attribute of the <customErrors> tag to use a custom page as follows:

(good)
Example Language: ASP.NET 
<customErrors mode="On" defaultRedirect="YourErrorPage.htm" />
+ Potential Mitigations

Phase: System Configuration

Handle exceptions appropriately in source code. ASP .NET applications should be configured to use custom error pages instead of the framework default page.

Phase: Architecture and Design

Do not attempt to process an error or attempt to mask it.

Phase: Implementation

Verify return values are correct and do not supply sensitive information about the system.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory27PK - Environment
MemberOfCategoryCategory963SFP Secondary Cluster: Exposed Data
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
7 Pernicious KingdomsASP.NET Misconfiguration: Missing Custom Error Handling
+ References
[REF-65] M. Howard, D. LeBlanc and J. Viega. "19 Deadly Sins of Software Security". McGraw-Hill/Osborne. 2005-07-26.
[REF-66] OWASP, Fortify Software. "ASP.NET Misconfiguration: Missing Custom Error Handling". <http://www.owasp.org/index.php/ASP.NET_Misconfiguration:_Missing_Custom_Error_Handling>.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
7 Pernicious Kingdoms
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated References, Demonstrative_Example, Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes, References, Taxonomy_Mappings
2008-10-14CWE Content TeamMITRE
updated Relationships
2008-11-24CWE Content TeamMITRE
updated Common_Consequences, Other_Notes, Potential_Mitigations
2009-03-10CWE Content TeamMITRE
updated Name, Relationships
2009-07-27CWE Content TeamMITRE
updated Background_Details, Common_Consequences, Other_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2013-02-21CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples, Potential_Mitigations, References, Relationships
Previous Entry Names
Change DatePrevious Entry Name
2009-03-10ASP.NET Misconfiguration: Missing Custom Error Handling

CWE-554: ASP.NET Misconfiguration: Not Using Input Validation Framework

Weakness ID: 554
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The ASP.NET application does not use an input validation framework.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass20Improper Input Validation
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory519.NET Environment Issues
ChildOfClassClass20Improper Input Validation
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

ASP.NET: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity

Technical Impact: Unexpected State

Unchecked input leads to cross-site scripting, process control, and SQL injection vulnerabilities, among others.
+ Potential Mitigations

Phase: Architecture and Design

Use the ASP.NET validation framework to check all program input before it is processed by the application. Example uses of the validation framework include checking to ensure that: Phone number fields contain only valid characters in phone numbers Boolean values are only "T" or "F" Free-form strings are of a reasonable length and composition
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory990SFP Secondary Cluster: Tainted Input to Command
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
Software Fault PatternsSFP24Tainted input to command
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
Anonymous Tool Vendor (under NDA)
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Relationships, Other_Notes, Taxonomy_Mappings, Type
2009-07-27CWE Content TeamMITRE
updated Other_Notes
2011-03-29CWE Content TeamMITRE
updated Common_Consequences, Description, Potential_Mitigations
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-01-19CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11ASP.NET Misconfiguration: Input Validation

CWE-13: ASP.NET Misconfiguration: Password in Configuration File

Weakness ID: 13
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
Storing a plaintext password in a configuration file allows anyone who can read the file access to the password-protected resource making them an easy target for attackers.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfVariantVariant260Password in Configuration File
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory519.NET Environment Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Gain Privileges or Assume Identity

+ Demonstrative Examples

Example 1

The following excerpt from an XML configuration file defines a connectionString for connecting to a database.

(bad)
Example Language: XML 
<connectionStrings>
<add name="ud_DEV" connectionString="connectDB=uDB; uid=db2admin; pwd=password; dbalias=uDB;"
providerName="System.Data.Odbc" />

</connectionStrings>

The connectionString is in cleartext, allowing anyone who can read the file access to the database.

Example 2

The following example shows a portion of a configuration file for an ASP.Net application. This configuration file includes username and password information for a connection to a database but the pair is stored in plaintext.

(bad)
Example Language: ASP.NET 
...
<connectionStrings>
<add name="ud_DEV" connectionString="connectDB=uDB; uid=db2admin; pwd=password; dbalias=uDB;" providerName="System.Data.Odbc" />
</connectionStrings>
...

Username and password information should not be included in a configuration file or a properties file in plaintext as this will allow anyone who can read the file access to the resource. If possible, encrypt this information.

+ Potential Mitigations

Phase: Implementation

Credentials stored in configuration files should be encrypted, Use standard APIs and industry accepted algorithms to encrypt the credentials stored in configuration files.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory27PK - Environment
MemberOfCategoryCategory963SFP Secondary Cluster: Exposed Data
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
7 Pernicious KingdomsASP.NET Misconfiguration: Password in Configuration File
+ References
[REF-103] Microsoft Corporation. "How To: Encrypt Configuration Sections in ASP.NET 2.0 Using DPAPI". <http://msdn.microsoft.com/en-us/library/ms998280.aspx>.
[REF-104] Microsoft Corporation. "How To: Encrypt Configuration Sections in ASP.NET 2.0 Using RSA". <http://msdn.microsoft.com/en-us/library/ms998283.aspx>.
[REF-105] Microsoft Corporation. ".NET Framework Developer's Guide - Securing Connection Strings". <http://msdn.microsoft.com/en-us/library/89211k9b(VS.80).aspx>.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
7 Pernicious Kingdoms
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated References, Demonstrative_Example, Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, References, Taxonomy_Mappings
2009-07-27CWE Content TeamMITRE
updated Demonstrative_Examples
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2012-10-30CWE Content TeamMITRE
updated Demonstrative_Examples
2013-02-21CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2017-11-08CWE Content TeamMITRE
updated Relationships

CWE-556: ASP.NET Misconfiguration: Use of Identity Impersonation

Weakness ID: 556
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
Configuring an ASP.NET application to run with impersonated credentials may give the application unnecessary privileges.
+ Extended Description
The use of impersonated credentials allows an ASP.NET application to run with either the privileges of the client on whose behalf it is executing or with arbitrary privileges granted in its configuration.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfBaseBase266Incorrect Privilege Assignment
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory519.NET Environment Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
Operation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Gain Privileges or Assume Identity

+ Potential Mitigations

Phase: Architecture and Design

Use the least privilege principle.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
Anonymous Tool Vendor (under NDA)
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2008-10-14CWE Content TeamMITRE
updated Description
2009-03-10CWE Content TeamMITRE
updated Relationships
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11ASP.NET Misconfiguration: Identity Impersonation

CWE-481: Assigning instead of Comparing

Weakness ID: 481
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The code uses an operator for assignment when the intention was to perform a comparison.
+ Extended Description
In many languages the compare statement is very close in appearance to the assignment statement and are often confused. This bug is generally the result of a typo and usually causes obvious problems with program execution. If the comparison is in an if statement, the if statement will usually evaluate the value of the right-hand side of the predicate.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfBaseBase480Use of Incorrect Operator
CanPrecedeClassClass697Insufficient Comparison
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfBaseBase480Use of Incorrect Operator
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C: (Undetermined Prevalence)

C++: (Undetermined Prevalence)

Java: (Undetermined Prevalence)

C#: (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Other

Technical Impact: Alter Execution Logic

+ Likelihood Of Exploit
Low
+ Demonstrative Examples

Example 1

The following C/C++ and C# examples attempt to validate an int input parameter against the integer value 100.

(bad)
Example Language:
int isValid(int value) {
if (value=100) {
printf("Value is valid\n");
return(1);

}
printf("Value is not valid\n");
return(0);

}
(bad)
Example Language: C# 
bool isValid(int value) {
if (value=100) {
Console.WriteLine("Value is valid.");
return true;

}
Console.WriteLine("Value is not valid.");
return false;

}

However, the expression to be evaluated in the if statement uses the assignment operator "=" rather than the comparison operator "==". The result of using the assignment operator instead of the comparison operator causes the int variable to be reassigned locally and the expression in the if statement will always evaluate to the value on the right hand side of the expression. This will result in the input value not being properly validated, which can cause unexpected results.

Example 2

In this example, we show how assigning instead of comparing can impact code when values are being passed by reference instead of by value. Consider a scenario in which a string is being processed from user input. Assume the string has already been formatted such that different user inputs are concatenated with the colon character. When the processString function is called, the test for the colon character will result in an insertion of the colon character instead, adding new input separators. Since the string was passed by reference, the data sentinels will be inserted in the original string (CWE-464), and further processing of the inputs will be altered, possibly malformed..

(bad)
Example Language:
void processString (char *str) {
int i;

for(i=0; i<strlen(str); i++) {
if (isalnum(str[i])){
processChar(str[i]);

}
else if (str[i] = ':') {
movingToNewInput();}

}

}

}

Example 3

The following Java example attempts to perform some processing based on the boolean value of the input parameter. However, the expression to be evaluated in the if statement uses the assignment operator "=" rather than the comparison operator "==". As with the previous examples, the variable will be reassigned locally and the expression in the if statement will evaluate to true and unintended processing may occur.

(bad)
Example Language: Java 
public void checkValid(boolean isValid) {
if (isValid = true) {
System.out.println("Performing processing");
doSomethingImportant();

}
else {
System.out.println("Not Valid, do not perform processing");
return;

}

}

While most Java compilers will catch the use of an assignment operator when a comparison operator is required, for boolean variables in Java the use of the assignment operator within an expression is allowed. If possible, try to avoid using comparison operators on boolean variables in java. Instead, let the values of the variables stand for themselves, as in the following code.

(good)
Example Language: Java 
public void checkValid(boolean isValid) {
if (isValid) {
System.out.println("Performing processing");
doSomethingImportant();

}
else {
System.out.println("Not Valid, do not perform processing");
return;

}

}

Alternatively, to test for false, just use the boolean NOT operator.

(good)
Example Language: Java 
public void checkValid(boolean isValid) {
if (!isValid) {
System.out.println("Not Valid, do not perform processing");
return;

}
System.out.println("Performing processing");
doSomethingImportant();

}

Example 4

The following example demonstrates the weakness.

(bad)
Example Language:
void called(int foo){
if (foo=1) printf("foo\n");

}
int main() {

called(2);
return 0;

}
+ Potential Mitigations

Phase: Testing

Many IDEs and static analysis products will detect this problem.

Phase: Implementation

Place constants on the left. If one attempts to assign a constant with a variable, the compiler will of course produce an error.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory998SFP Secondary Cluster: Glitch in Computation
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CLASPAssigning instead of comparing
Software Fault PatternsSFP1Glitch in computation
CERT C Secure CodingEXP45-CCWE More AbstractDo not perform assignments in selection statements
+ References
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 6, "Typos", Page 289.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
CLASP
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Applicable_Platforms, Description, Relationships, Other_Notes, Taxonomy_Mappings
2009-05-27CWE Content TeamMITRE
updated Demonstrative_Examples
2009-07-27CWE Content TeamMITRE
updated Description, Other_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated References, Relationships
2012-10-30CWE Content TeamMITRE
updated Demonstrative_Examples, Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-01-19CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples, Taxonomy_Mappings

CWE-587: Assignment of a Fixed Address to a Pointer

Weakness ID: 587
Abstraction: Base
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The software sets a pointer to a specific address other than NULL or 0.
+ Extended Description
Using a fixed address is not portable because that address will probably not be valid in all environments or platforms.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory465Pointer Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C: (Undetermined Prevalence)

C++: (Undetermined Prevalence)

C#: (Undetermined Prevalence)

(Assembly classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity
Confidentiality
Availability

Technical Impact: Execute Unauthorized Code or Commands

If one executes code at a known location, an attacker might be able to inject code there beforehand.
Availability

Technical Impact: DoS: Crash, Exit, or Restart

If the code is ported to another platform or environment, the pointer is likely to be invalid and cause a crash.
Confidentiality
Integrity

Technical Impact: Read Memory; Modify Memory

The data at a known pointer location can be easily read or influenced by an attacker.
+ Demonstrative Examples

Example 1

This code assumes a particular function will always be found at a particular address. It assigns a pointer to that address and calls the function.

(bad)
Example Language:
int (*pt2Function) (float, char, char)=0x08040000;
int result2 = (*pt2Function) (12, 'a', 'b');
// Here we can inject code to execute.

The same function may not always be found at the same memory address. This could lead to a crash, or an attacker may alter the memory at the expected address, leading to arbitrary code execution.

+ Potential Mitigations

Phase: Implementation

Never set a pointer to a fixed address.
+ Weakness Ordinalities
OrdinalityDescription
Primary
(where the weakness exists independent of other weaknesses)
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CERT C Secure CodingINT36-CImpreciseConverting a pointer to integer or integer to pointer
Software Fault PatternsSFP1Glitch in computation
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-08-01KDM Analytics
added/updated white box definitions
2008-09-08CWE Content TeamMITRE
updated Applicable_Platforms, Description, Relationships, Other_Notes, Weakness_Ordinalities
2008-11-24CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2009-03-10CWE Content TeamMITRE
updated Relationships
2009-07-27CWE Content TeamMITRE
updated Common_Consequences, Description, Other_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-09-13CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Taxonomy_Mappings, White_Box_Definitions

CWE-563: Assignment to Variable without Use

Weakness ID: 563
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The variable's value is assigned but never used, making it a dead store.
+ Extended Description
After the assignment, the variable is either assigned another value or goes out of scope. It is likely that the variable is simply vestigial, but it is also possible that the unused variable points out a bug.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass710Improper Adherence to Coding Standards
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory1006Bad Coding Practices
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Other

Technical Impact: Quality Degradation; Varies by Context

This weakness could be an indication of a bug in the program or a deprecated variable that was not removed and is an indication of poor quality. This could lead to further bugs and the introduction of weaknesses.
+ Alternate Terms
Unused Variable
+ Demonstrative Examples

Example 1

The following code excerpt assigns to the variable r and then overwrites the value without using it.

(bad)
Example Language:
r = getName();
r = getNewBuffer(buf);
+ Potential Mitigations

Phase: Implementation

Remove unused variables from the code.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CERT C Secure CodingMSC00-CCompile cleanly at high warning levels
CERT Perl Secure CodingMSC01-PLImpreciseDetect and remove unused variables
Software Fault PatternsSFP2Unused Entities
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
Anonymous Tool Vendor (under NDA)
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Relationships, Other_Notes, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2009-05-27CWE Content TeamMITRE
updated Demonstrative_Examples
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2011-09-13CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-06-23CWE Content TeamMITRE
updated Common_Consequences, Description, Name, Other_Notes
2014-07-30CWE Content TeamMITRE
updated Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Alternate_Terms, Name, Relationships, Taxonomy_Mappings
Previous Entry Names
Change DatePrevious Entry Name
2014-06-23Unused Variable
2017-11-08Assignment to Variable without Use ('Unused Variable')

CWE-405: Asymmetric Resource Consumption (Amplification)

Weakness ID: 405
Abstraction: Class
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
Software that does not appropriately monitor or control resource consumption can lead to adverse system performance.
+ Extended Description
This situation is amplified if the software allows malicious users or attackers to consume more resources than their access level permits. Exploiting such a weakness can lead to asymmetric resource consumption, aiding in amplification attacks against the system or the network.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
NatureTypeIDName
ParentOfBaseBase407Algorithmic Complexity
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Operation
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Availability

Technical Impact: DoS: Amplification; DoS: Resource Consumption (Other)

Sometimes this is a factor in "flood" attacks, but other types of amplification exist.
+ Potential Mitigations

Phase: Architecture and Design

An application must make resources available to a client commensurate with the client's access level.

Phase: Architecture and Design

An application must, at all times, keep track of allocated resources and meter their usage appropriately.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAsymmetric resource consumption (amplification)
OWASP Top Ten 2004A9CWE More SpecificDenial of Service
WASC41XML Attribute Blowup
CERT Java Secure CodingTPS00-JUse thread pools to enable graceful degradation of service during traffic bursts
CERT Java Secure CodingFIO04-JRelease resources when they are no longer needed
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes, Taxonomy_Mappings
2008-10-14CWE Content TeamMITRE
updated Description
2009-07-27CWE Content TeamMITRE
updated Common_Consequences, Other_Notes
2010-02-16CWE Content TeamMITRE
updated Taxonomy_Mappings
2010-12-13CWE Content TeamMITRE
updated Description
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
2015-12-07CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Functional_Areas

CWE-588: Attempt to Access Child of a Non-structure Pointer

Weakness ID: 588
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
Casting a non-structure type to a structure type and accessing a field can lead to memory access errors or data corruption.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory465Pointer Issues
MemberOfCategoryCategory569Expression Issues
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity

Technical Impact: Modify Memory

Adjacent variables in memory may be corrupted by assignments performed on fields after the cast.
Availability

Technical Impact: DoS: Crash, Exit, or Restart

Execution may end due to a memory access error.
+ Demonstrative Examples

Example 1

The following example demonstrates the weakness.

(bad)
Example Language:
struct foo
{
int i;

}
...
int main(int argc, char **argv)
{
*foo = (struct foo *)main;
foo->i = 2;
return foo->i;

}
+ Potential Mitigations

Phase: Requirements

The choice could be made to use a language that is not susceptible to these issues.

Phase: Implementation

Review of type casting operations can identify locations where incompatible types are cast.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory971SFP Secondary Cluster: Faulty Pointer Use
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
Software Fault PatternsSFP7Faulty Pointer Use
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes
2009-03-10CWE Content TeamMITRE
updated Relationships
2009-07-27CWE Content TeamMITRE
updated Common_Consequences, Other_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples

CWE-289: Authentication Bypass by Alternate Name

Weakness ID: 289
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1010Authenticate Actors
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfClassClass287Improper Authentication
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignCOMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Bypass Protection Mechanism

+ Observed Examples
ReferenceDescription
Protection mechanism that restricts URL access can be bypassed using URL encoding.
Bypass of authentication for files using "\" (backslash) or "%5C" (encoded backslash).
+ Potential Mitigations

Phase: Architecture and Design

Strategy: Input Validation

Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.

Phase: Implementation

Strategy: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a whitelist of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs (i.e., do not rely on a blacklist). A blacklist is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, blacklists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Phase: Implementation

Strategy: Input Validation

Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass whitelist validation schemes by introducing dangerous inputs after they have been checked.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Notes

Relationship

Overlaps equivalent encodings, canonicalization, authorization, multiple trailing slash, trailing space, mixed case, and other equivalence issues.

Theoretical

Alternate names are useful in data driven manipulation attacks, not just for authentication.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAuthentication bypass by alternate name
CERT Java Secure CodingIDS01-JNormalize strings before validating them
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Relationships, Other_Notes, Relationship_Notes, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Observed_Examples
2009-07-27CWE Content TeamMITRE
updated Other_Notes, Potential_Mitigations, Theoretical_Notes
2011-03-29CWE Content TeamMITRE
updated Potential_Mitigations
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-05-03CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Modes_of_Introduction, Relationships

CWE-302: Authentication Bypass by Assumed-Immutable Data

Weakness ID: 302
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The authentication scheme or implementation uses key data elements that are assumed to be immutable, but can be controlled or modified by the attacker.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1010Authenticate Actors
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfClassClass287Improper Authentication
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignCOMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Bypass Protection Mechanism

+ Demonstrative Examples

Example 1

In the following example, an "authenticated" cookie is used to determine whether or not a user should be granted access to a system.

(bad)
Example Language: Java 
boolean authenticated = new Boolean(getCookieValue("authenticated")).booleanValue();
if (authenticated) {
...

}

Of course, modifying the value of a cookie on the client-side is trivial, but many developers assume that cookies are essentially immutable.

+ Observed Examples
ReferenceDescription
DebPloit
Web auth
Authentication bypass by setting certain cookies to "true".
Authentication bypass by setting certain cookies to "true".
Admin access by setting a cookie.
Gain privileges by setting cookie.
Product trusts authentication information in cookie.
Authentication bypass by setting admin-testing variable to true.
Bypass auth and gain privileges by setting a variable.
+ Potential Mitigations

Phases: Architecture and Design; Operation; Implementation

Implement proper protection for immutable data (e.g. environment variable, hidden form fields, etc.)
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAuthentication Bypass via Assumed-Immutable Data
OWASP Top Ten 2004A1CWE More SpecificUnvalidated Input
CERT Java Secure CodingSEC02-JDo not base security checks on untrusted sources
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Sean EidemillerCigital
added/updated demonstrative examples
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2008-10-14CWE Content TeamMITRE
updated Demonstrative_Examples, Description
2009-03-10CWE Content TeamMITRE
updated Relationships
2010-02-16CWE Content TeamMITRE
updated Potential_Mitigations, Relationships
2010-04-05CWE Content TeamMITRE
updated Related_Attack_Patterns
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2014-07-30CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2017-05-03CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Modes_of_Introduction, Relationships

CWE-305: Authentication Bypass by Primary Weakness

Weakness ID: 305
Abstraction: Base
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass287Improper Authentication
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1010Authenticate Actors
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfClassClass287Improper Authentication
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
ImplementationREALIZATION: This weakness is caused during implementation of an architectural security tactic.
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Bypass Protection Mechanism

+ Observed Examples
ReferenceDescription
The provided password is only compared against the first character of the real password.
The password is not properly checked, which allows remote attackers to bypass access controls by sending a 1-byte password that matches the first character of the real password.
Chain: Forum software does not properly initialize an array, which inadvertently sets the password to a single character, allowing remote attackers to easily guess the password and gain administrative privileges.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory947SFP Secondary Cluster: Authentication Bypass
+ Notes

Relationship

Most "authentication bypass" errors are resultant, not primary.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAuthentication Bypass by Primary Weakness
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Relationship_Notes, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Observed_Examples
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Observed_Examples, Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-05-03CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Modes_of_Introduction, Relationships

CWE-290: Authentication Bypass by Spoofing

Weakness ID: 290
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
This attack-focused weakness is caused by improperly implemented authentication schemes that are subject to spoofing attacks.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1010Authenticate Actors
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignCOMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Implementation
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity

This weakness can allow an attacker to access resources which are not otherwise accessible without proper authentication.
+ Demonstrative Examples

Example 1

The following code authenticates users.

(bad)
Example Language: Java 
String sourceIP = request.getRemoteAddr();
if (sourceIP != null && sourceIP.equals(APPROVED_IP)) {
authenticated = true;

}

The authentication mechanism implemented relies on an IP address for source validation. If an attacker is able to spoof the IP, they may be able to bypass the authentication mechanism.

Example 2

Both of these examples check if a request is from a trusted address before responding to the request.

(bad)
Example Language:
sd = socket(AF_INET, SOCK_DGRAM, 0);
serv.sin_family = AF_INET;
serv.sin_addr.s_addr = htonl(INADDR_ANY);
servr.sin_port = htons(1008);
bind(sd, (struct sockaddr *) & serv, sizeof(serv));

while (1) {
memset(msg, 0x0, MAX_MSG);
clilen = sizeof(cli);
if (inet_ntoa(cli.sin_addr)==getTrustedAddress()) {
n = recvfrom(sd, msg, MAX_MSG, 0, (struct sockaddr *) & cli, &clilen);

}

}
(bad)
Example Language: Java 
while(true) {
DatagramPacket rp=new DatagramPacket(rData,rData.length);
outSock.receive(rp);
String in = new String(p.getData(),0, rp.getLength());
InetAddress clientIPAddress = rp.getAddress();
int port = rp.getPort();

if (isTrustedAddress(clientIPAddress) & secretKey.equals(in)) {
out = secret.getBytes();
DatagramPacket sp =new DatagramPacket(out,out.length, IPAddress, port); outSock.send(sp);

}

}

The code only verifies the address as stored in the request packet. An attacker can spoof this address, thus impersonating a trusted client

Example 3

The following code samples use a DNS lookup in order to decide whether or not an inbound request is from a trusted host. If an attacker can poison the DNS cache, they can gain trusted status.

(bad)
Example Language:
struct hostent *hp;struct in_addr myaddr;
char* tHost = "trustme.example.com";
myaddr.s_addr=inet_addr(ip_addr_string);

hp = gethostbyaddr((char *) &myaddr, sizeof(struct in_addr), AF_INET);
if (hp && !strncmp(hp->h_name, tHost, sizeof(tHost))) {
trusted = true;

} else {
trusted = false;

}
(bad)
Example Language: Java 
String ip = request.getRemoteAddr();
InetAddress addr = InetAddress.getByName(ip);
if (addr.getCanonicalHostName().endsWith("trustme.com")) {
trusted = true;

}
(bad)
Example Language: C# 
IPAddress hostIPAddress = IPAddress.Parse(RemoteIpAddress);
IPHostEntry hostInfo = Dns.GetHostByAddress(hostIPAddress);
if (hostInfo.HostName.EndsWith("trustme.com")) {
trusted = true;

}

IP addresses are more reliable than DNS names, but they can also be spoofed. Attackers can easily forge the source IP address of the packets they send, but response packets will return to the forged IP address. To see the response packets, the attacker has to sniff the traffic between the victim machine and the forged IP address. In order to accomplish the required sniffing, attackers typically attempt to locate themselves on the same subnet as the victim machine. Attackers may be able to circumvent this requirement by using source routing, but source routing is disabled across much of the Internet today. In summary, IP address verification can be a useful part of an authentication scheme, but it should not be the single factor required for authentication.

+ Observed Examples
ReferenceDescription
VOIP product allows authentication bypass using 127.0.0.1 in the Host header.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfViewView884CWE Cross-section
MemberOfCategoryCategory956SFP Secondary Cluster: Channel Attack
+ Notes

Relationship

This can be resultant from insufficient verification.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAuthentication bypass by spoofing
+ References
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 3, "Spoofing and Identification", Page 72.. 1st Edition. Addison Wesley. 2006.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Sean EidemillerCigital
added/updated demonstrative examples
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Relationships, Relationship_Notes, Taxonomy_Mappings
2009-07-27CWE Content TeamMITRE
updated Relationship_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Demonstrative_Examples, Observed_Examples, References, Related_Attack_Patterns, Relationships
2013-07-17CWE Content TeamMITRE
updated Relationships
2014-02-18CWE Content TeamMITRE
updated Related_Attack_Patterns
2014-07-30CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2017-05-03CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples, Modes_of_Introduction, Relationships

CWE-593: Authentication Bypass: OpenSSL CTX Object Modified after SSL Objects are Created

Weakness ID: 593
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The software modifies the SSL context after connection creation has begun.
+ Extended Description
If the program modifies the SSL_CTX object after creating SSL objects from it, there is the possibility that older SSL objects created from the original context could all be affected by that change.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1010Authenticate Actors
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfClassClass287Improper Authentication
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
ImplementationREALIZATION: This weakness is caused during implementation of an architectural security tactic.
+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Bypass Protection Mechanism

No authentication takes place in this process, bypassing an assumed protection of encryption.
Confidentiality

Technical Impact: Read Application Data

The encrypted communication between a user and a trusted host may be subject to a "man in the middle" sniffing attack.
+ Demonstrative Examples

Example 1

The following example demonstrates the weakness.

(bad)
Example Language:
#define CERT "secret.pem"
#define CERT2 "secret2.pem"

int main(){
SSL_CTX *ctx;
SSL *ssl;
init_OpenSSL();
seed_prng();

ctx = SSL_CTX_new(SSLv23_method());

if (SSL_CTX_use_certificate_chain_file(ctx, CERT) != 1)
int_error("Error loading certificate from file");


if (SSL_CTX_use_PrivateKey_file(ctx, CERT, SSL_FILETYPE_PEM) != 1)
int_error("Error loading private key from file");


if (!(ssl = SSL_new(ctx)))
int_error("Error creating an SSL context");


if ( SSL_CTX_set_default_passwd_cb(ctx, "new default password" != 1))
int_error("Doing something which is dangerous to do anyways");


if (!(ssl2 = SSL_new(ctx)))
int_error("Error creating an SSL context");

}
+ Potential Mitigations

Phase: Architecture and Design

Use a language or a library that provides a cryptography framework at a higher level of abstraction.

Phase: Implementation

Most SSL_CTX functions have SSL counterparts that act on SSL-type objects.

Phase: Implementation

Applications should set up an SSL_CTX completely, before creating SSL objects from it.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory948SFP Secondary Cluster: Digital Certificate
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Common_Consequences, Relationships, Other_Notes
2009-07-27CWE Content TeamMITRE
updated Description, Other_Notes, Potential_Mitigations
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-05-03CWE Content TeamMITRE
updated Potential_Mitigations, Relationships
2017-11-08CWE Content TeamMITRE
updated Demonstrative_Examples, Modes_of_Introduction, Relationships

CWE-566: Authorization Bypass Through User-Controlled SQL Primary Key

Weakness ID: 566
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software uses a database table that includes records that should not be accessible to an actor, but it executes a SQL statement with a primary key that can be controlled by that actor.
+ Extended Description

When a user can set a primary key to any value, then the user can modify the key to point to unauthorized records.

Database access control errors occur when:

  • Data enters a program from an untrusted source.
  • The data is used to specify the value of a primary key in a SQL query.
  • The untrusted source does not have the permissions to be able to access all rows in the associated table.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
NatureTypeIDName
MemberOfCategoryCategory1011Authorize Actors
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignCOMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Technologies

Database Server: (Often Prevalent)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Confidentiality
Integrity
Access Control

Technical Impact: Read Application Data; Modify Application Data; Bypass Protection Mechanism

+ Demonstrative Examples

Example 1

The following code uses a parameterized statement, which escapes metacharacters and prevents SQL injection vulnerabilities, to construct and execute a SQL query that searches for an invoice matching the specified identifier [1]. The identifier is selected from a list of all invoices associated with the current authenticated user.

(bad)
Example Language: C# 
...
conn = new SqlConnection(_ConnectionString);
conn.Open();
int16 id = System.Convert.ToInt16(invoiceID.Text);
SqlCommand query = new SqlCommand( "SELECT * FROM invoices WHERE id = @id", conn);
query.Parameters.AddWithValue("@id", id);
SqlDataReader objReader = objCommand.ExecuteReader();
...

The problem is that the developer has not considered all of the possible values of id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker can bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.

+ Potential Mitigations

Phase: Implementation

Assume all input is malicious. Use a standard input validation mechanism to validate all input for length, type, syntax, and business rules before accepting the data. Use an "accept known good" validation strategy.

Phase: Implementation

Use a parameterized query AND make sure that the accepted values conform to the business rules. Construct your SQL statement accordingly.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory994SFP Secondary Cluster: Tainted Input to Variable
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
Software Fault PatternsSFP25Tainted input to variable
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
Anonymous Tool Vendor (under NDA)
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes, Taxonomy_Mappings
2009-07-27CWE Content TeamMITRE
updated Demonstrative_Examples, Description, Other_Notes, Potential_Mitigations, Taxonomy_Mappings
2010-06-21CWE Content TeamMITRE
updated Description
2011-03-29CWE Content TeamMITRE
updated Applicable_Platforms, Demonstrative_Examples, Name
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Modes_of_Introduction, Relationships
Previous Entry Names
Change DatePrevious Entry Name
2011-03-29Access Control Bypass Through User-Controlled SQL Primary Key

CWE-439: Behavioral Change in New Version or Environment

Weakness ID: 439
Abstraction: Base
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
A's behavior or functionality changes with a new version of A, or a new environment, which is not known (or manageable) by B.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass435Improper Interaction Between Multiple Entities
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory438Behavioral Problems
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

(Language-Independent classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Other

Technical Impact: Quality Degradation; Varies by Context

+ Alternate Terms
Functional change
+ Observed Examples
ReferenceDescription
Linux kernel 2.2 and above allow promiscuous mode using a different method than previous versions, and ifconfig is not aware of the new method (alternate path property).
Product uses defunct method from another product that does not return an error code and allows detection avoidance.
chain: Code was ported from a case-sensitive Unix platform to a case-insensitive Windows platform where filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory1001SFP Secondary Cluster: Use of an Improper API
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERCHANGE Behavioral Change
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVER
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Observed_Example, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Observed_Examples
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Behavioral Change

CWE-806: Buffer Access Using Size of Source Buffer

Weakness ID: 806
Abstraction: Variant
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software uses the size of a source buffer when reading from or writing to a destination buffer, which may cause it to access memory that is outside of the bounds of the buffer.
+ Extended Description
When the size of the destination is smaller than the size of the source, a buffer overflow could occur.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfBaseBase805Buffer Access with Incorrect Length Value
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfBaseBase805Buffer Access with Incorrect Length Value
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C: (Sometimes Prevalent)

C++: (Sometimes Prevalent)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity
Confidentiality
Availability

Technical Impact: Execute Unauthorized Code or Commands

Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy.
Access Control

Technical Impact: Bypass Protection Mechanism

When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
+ Demonstrative Examples

Example 1

In the following example, the source character string is copied to the dest character string using the method strncpy.

(bad)
Example Language:
...
char source[21] = "the character string";
char dest[12];
strncpy(dest, source, sizeof(source)-1);
...

However, in the call to strncpy the source character string is used within the sizeof call to determine the number of characters to copy. This will create a buffer overflow as the size of the source character string is greater than the dest character string. The dest character string should be used within the sizeof call to ensure that the correct number of characters are copied, as shown below.

(good)
Example Language:
...
char source[21] = "the character string";
char dest[12];
strncpy(dest, source, sizeof(dest)-1);
...

Example 2

In this example, the method outputFilenameToLog outputs a filename to a log file. The method arguments include a pointer to a character string containing the file name and an integer for the number of characters in the string. The filename is copied to a buffer where the buffer size is set to a maximum size for inputs to the log file. The method then calls another method to save the contents of the buffer to the log file.

(bad)
Example Language:
#define LOG_INPUT_SIZE 40
// saves the file name to a log file

int outputFilenameToLog(char *filename, int length) {
int success;
// buffer with size set to maximum size for input to log file

char buf[LOG_INPUT_SIZE];
// copy filename to buffer

strncpy(buf, filename, length);
// save to log file

success = saveToLogFile(buf);

return success;

}

However, in this case the string copy method, strncpy, mistakenly uses the length method argument to determine the number of characters to copy rather than using the size of the local character string, buf. This can lead to a buffer overflow if the number of characters contained in character string pointed to by filename is larger then the number of characters allowed for the local character string. The string copy method should use the buf character string within a sizeof call to ensure that only characters up to the size of the buf array are copied to avoid a buffer overflow, as shown below.

(good)
Example Language:
...
// copy filename to buffer

strncpy(buf, filename, sizeof(buf)-1);
...
+ Potential Mitigations

Phase: Architecture and Design

Use an abstraction library to abstract away risky APIs. Examples include the Safe C String Library (SafeStr) by Viega, and the Strsafe.h library from Microsoft. This is not a complete solution, since many buffer overflows are not related to strings.

Phase: Build and Compilation

Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include StackGuard, ProPolice and the Microsoft Visual Studio /GS flag. This is not necessarily a complete solution, since these canary-based mechanisms only detect certain types of overflows. In addition, the result is still a denial of service, since the typical response is to exit the application.

Phase: Implementation

Programmers should adhere to the following rules when allocating and managing their applications memory: Double check that your buffer is as large as you specify. When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string. Check buffer boundaries if calling this function in a loop and make sure you are not in danger of writing past the allocated space. Truncate all input strings to a reasonable length before passing them to the copy and concatenation functions

Phase: Operation

Strategy: Environment Hardening

Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code. Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64].

Effectiveness: Defense in Depth

This is not a complete solution. However, it forces the attacker to guess an unknown value that changes every program execution. In addition, an attack could still cause a denial of service, since the typical response is to exit the application.

Phase: Operation

Strategy: Environment Hardening

Use a CPU and operating system that offers Data Execution Protection (NX) or its equivalent [REF-60] [REF-61].

Effectiveness: Defense in Depth

This is not a complete solution, since buffer overflows could be used to overwrite nearby variables to modify the software's state in dangerous ways. In addition, it cannot be used in cases in which self-modifying code is required. Finally, an attack could still cause a denial of service, since the typical response is to exit the application.

Phases: Build and Compilation; Operation

Most mitigating technologies at the compiler or OS level to date address only a subset of buffer overflow problems and rarely provide complete protection against even that subset. It is good practice to implement strategies to increase the workload of an attacker, such as leaving the attacker to guess an unknown value that changes every program execution.
+ Weakness Ordinalities
OrdinalityDescription
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Primary
(where the weakness exists independent of other weaknesses)
+ Affected Resources
  • Memory
+ References
[REF-56] Microsoft. "Using the Strsafe.h Functions". <http://msdn.microsoft.com/en-us/library/ms647466.aspx>.
[REF-57] Matt Messier and John Viega. "Safe C String Library v1.0.3". <http://www.zork.org/safestr/>.
[REF-58] Michael Howard. "Address Space Layout Randomization in Windows Vista". <http://blogs.msdn.com/michael_howard/archive/2006/05/26/address-space-layout-randomization-in-windows-vista.aspx>.
[REF-59] Arjan van de Ven. "Limiting buffer overflows with ExecShield". <http://www.redhat.com/magazine/009jul05/features/execshield/>.
[REF-61] Microsoft. "Understanding DEP as a mitigation technology part 1". <http://blogs.technet.com/b/srd/archive/2009/06/12/understanding-dep-as-a-mitigation-technology-part-1.aspx>.
[REF-64] Grant Murphy. "Position Independent Executables (PIE)". Red Hat. 2012-11-28. <https://securityblog.redhat.com/2012/11/28/position-independent-executables-pie/>.
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
2010-01-15CWE Content TeamMITRE
Modifications
Modification DateModifierOrganizationSource
2011-03-29CWE Content TeamMITRE
updated Demonstrative_Examples
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Potential_Mitigations, References
2014-02-18CWE Content TeamMITRE
updated Potential_Mitigations, References
2017-11-08CWE Content TeamMITRE
updated Causal_Nature, Demonstrative_Examples, Likelihood_of_Exploit, References

CWE-805: Buffer Access with Incorrect Length Value

Weakness ID: 805
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The software uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.
+ Extended Description
When the length value exceeds the size of the destination, a buffer overflow could occur.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C: (Often Prevalent)

C++: (Often Prevalent)

(Assembly classes): (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Integrity
Confidentiality
Availability

Technical Impact: Execute Unauthorized Code or Commands

Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. This can often be used to subvert any other security service.
Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

This example takes an IP address from a user, verifies that it is well formed and then looks up the hostname and copies it into a buffer.

(bad)
Example Language:
void host_lookup(char *user_supplied_addr){
struct hostent *hp;
in_addr_t *addr;
char hostname[64];
in_addr_t inet_addr(const char *cp);
/*routine that ensures user_supplied_addr is in the right format for conversion */

validate_addr_form(user_supplied_addr);
addr = inet_addr(user_supplied_addr);
hp = gethostbyaddr( addr, sizeof(struct in_addr), AF_INET);
strcpy(hostname, hp->h_name);

}

This function allocates a buffer of 64 bytes to store the hostname under the assumption that the maximum length value of hostname is 64 bytes, however there is no guarantee that the hostname will not be larger than 64 bytes. If an attacker specifies an address which resolves to a very large hostname, then we may overwrite sensitive data or even relinquish control flow to the attacker.

Note that this example also contains an unchecked return value (CWE-252) that can lead to a NULL pointer dereference (CWE-476).

Example 2

In the following example, it is possible to request that memcpy move a much larger segment of memory than assumed:

(bad)
Example Language:
int returnChunkSize(void *) {
/* if chunk info is valid, return the size of usable memory,
* else, return -1 to indicate an error
*/
...

}
int main() {
...
memcpy(destBuf, srcBuf, (returnChunkSize(destBuf)-1));
...

}

If returnChunkSize() happens to encounter an error it will return -1. Notice that the return value is not checked before the memcpy operation (CWE-252), so -1 can be passed as the size argument to memcpy() (CWE-805). Because memcpy() assumes that the value is unsigned, it will be interpreted as MAXINT-1 (CWE-195), and therefore will copy far more memory than is likely available to the destination buffer (CWE-787, CWE-788).

Example 3

In the following example, the source character string is copied to the dest character string using the method strncpy.

(bad)
Example Language:
...
char source[21] = "the character string";
char dest[12];
strncpy(dest, source, sizeof(source)-1);
...

However, in the call to strncpy the source character string is used within the sizeof call to determine the number of characters to copy. This will create a buffer overflow as the size of the source character string is greater than the dest character string. The dest character string should be used within the sizeof call to ensure that the correct number of characters are copied, as shown below.

(good)
Example Language:
...
char source[21] = "the character string";
char dest[12];
strncpy(dest, source, sizeof(dest)-1);
...

Example 4

In this example, the method outputFilenameToLog outputs a filename to a log file. The method arguments include a pointer to a character string containing the file name and an integer for the number of characters in the string. The filename is copied to a buffer where the buffer size is set to a maximum size for inputs to the log file. The method then calls another method to save the contents of the buffer to the log file.

(bad)
Example Language:
#define LOG_INPUT_SIZE 40
// saves the file name to a log file

int outputFilenameToLog(char *filename, int length) {
int success;
// buffer with size set to maximum size for input to log file

char buf[LOG_INPUT_SIZE];
// copy filename to buffer

strncpy(buf, filename, length);
// save to log file

success = saveToLogFile(buf);

return success;

}

However, in this case the string copy method, strncpy, mistakenly uses the length method argument to determine the number of characters to copy rather than using the size of the local character string, buf. This can lead to a buffer overflow if the number of characters contained in character string pointed to by filename is larger then the number of characters allowed for the local character string. The string copy method should use the buf character string within a sizeof call to ensure that only characters up to the size of the buf array are copied to avoid a buffer overflow, as shown below.

(good)
Example Language:
...
// copy filename to buffer

strncpy(buf, filename, sizeof(buf)-1);
...
+ Observed Examples
ReferenceDescription
Chain: large length value causes buffer over-read (CWE-126)
Use of packet length field to make a calculation, then copy into a fixed-size buffer
Chain: retrieval of length value from an uninitialized memory location
Crafted length value in document reader leads to buffer overflow
SSL server overflow when the sum of multiple length fields exceeds a given value
Language interpreter API function doesn't validate length argument, leading to information exposure
+ Potential Mitigations

Phase: Requirements

Strategy: Language Selection

Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.
This is not a complete solution, since many buffer overflows are not related to strings.

Phase: Build and Compilation

Strategy: Compilation or Build Hardening

Run or compile the software using features or extensions that automatically provide a protection mechanism that mitigates or eliminates buffer overflows. For example, certain compilers and extensions provide automatic buffer overflow detection mechanisms that are built into the compiled code. Examples include the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice.

Effectiveness: Defense in Depth

This is not necessarily a complete solution, since these mechanisms can only detect certain types of overflows. In addition, an attack could still cause a denial of service, since the typical response is to exit the application.

Phase: Implementation

Consider adhering to the following rules when allocating and managing an application's memory: