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Common Weakness Enumeration

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Home > CWE List > CWE-112: Missing XML Validation (4.16)  
ID

CWE-112: Missing XML Validation

Weakness ID: 112
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
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+ Description
The product accepts XML from an untrusted source but does not validate the XML against the proper schema.
+ Extended Description
Most successful attacks begin with a violation of the programmer's assumptions. By accepting an XML document without validating it against a DTD or XML schema, the programmer leaves a door open for attackers to provide unexpected, unreasonable, or malicious input.
+ Common Consequences
Section HelpThis table 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.
Scope Impact Likelihood
Integrity

Technical Impact: Unexpected State

+ Potential Mitigations

Phase: Architecture and Design

Strategy: Input Validation

Always validate XML input against a known XML Schema or DTD.

It is not possible for an XML parser to validate all aspects of a document's content because a parser cannot understand the complete semantics of the data. However, a parser can do a complete and thorough job of checking the document's structure and therefore guarantee to the code that processes the document that the content is well-formed.

+ Relationships
Section Help This table 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)
Nature Type ID Name
ChildOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 1286 Improper Validation of Syntactic Correctness of Input
Section Help This table 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 "Software Development" (CWE-699)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1215 Data Validation Issues
Section Help This table 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 "Seven Pernicious Kingdoms" (CWE-700)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 20 Improper Input Validation
+ Modes Of Introduction
Section HelpThe different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
Phase Note
Implementation
+ Applicable Platforms
Section HelpThis listing shows 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

Class: Not Language-Specific (Undetermined Prevalence)

+ Demonstrative Examples

Example 1

The following code loads and parses an XML file.

(bad code)
Example Language: Java 

// Read DOM
try {
...
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating( false );
....
c_dom = factory.newDocumentBuilder().parse( xmlFile );
} catch(Exception ex) {
...
}

The XML file is loaded without validating it against a known XML Schema or DTD.


Example 2

The following code creates a DocumentBuilder object to be used in building an XML document.

(bad code)
Example Language: Java 
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
builderFactory.setNamespaceAware(true);
DocumentBuilder builder = builderFactory.newDocumentBuilder();

The DocumentBuilder object does not validate an XML document against a schema, making it possible to create an invalid XML document.


+ Weakness Ordinalities
Ordinality Description
Primary
(where the weakness exists independent of other weaknesses)
+ Detection Methods

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Effectiveness: High

+ Memberships
Section HelpThis 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.
Nature Type ID Name
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 990 SFP Secondary Cluster: Tainted Input to Command
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1406 Comprehensive Categorization: Improper Input Validation
+ Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID may be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
7 Pernicious Kingdoms Missing XML Validation
Software Fault Patterns SFP24 Tainted input to command
+ References
[REF-6] Katrina Tsipenyuk, Brian Chess and Gary McGraw. "Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors". NIST Workshop on Software Security Assurance Tools Techniques and Metrics. NIST. 2005-11-07. <https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf>.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
7 Pernicious Kingdoms
+ Modifications
Modification Date Modifier Organization
2008-07-01 Sean Eidemiller Cigital
added/updated demonstrative examples
2008-07-01 Eric Dalci Cigital
updated Demonstrative_Example, Potential_Mitigations, Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2008-11-24 CWE Content Team MITRE
updated Description, Other_Notes
2009-05-27 CWE Content Team MITRE
updated Demonstrative_Examples
2009-10-29 CWE Content Team MITRE
updated Description
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2011-06-27 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Relationships
2013-02-21 CWE Content Team MITRE
updated Potential_Mitigations
2014-02-18 CWE Content Team MITRE
updated Related_Attack_Patterns
2014-06-23 CWE Content Team MITRE
updated Demonstrative_Examples, Other_Notes, Potential_Mitigations
2014-07-30 CWE Content Team MITRE
updated Demonstrative_Examples, Relationships, Taxonomy_Mappings
2017-01-19 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Causal_Nature, Relationships
2019-01-03 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated References, Related_Attack_Patterns, Relationships
2020-06-25 CWE Content Team MITRE
updated Relationships
2023-01-31 CWE Content Team MITRE
updated Description
2023-04-27 CWE Content Team MITRE
updated Detection_Factors, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
Page Last Updated: November 19, 2024