Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

CWE/SANS Top 25 Most Dangerous Software Errors
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CWE-272: Least Privilege Violation

Weakness ID: 272
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The elevated privilege level required to perform operations such as chroot() should be dropped immediately after the operation is performed.
+ 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)
ChildOfClassClass271Privilege Dropping / Lowering Errors
+ Relevant to the view "Architectural Concepts" (CWE-1008)
MemberOfCategoryCategory1011Authorize Actors
+ Relevant to the view "Development Concepts" (CWE-699)
ChildOfClassClass271Privilege Dropping / Lowering Errors
+ 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.

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.


Class: Language-Independent (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.

Access Control

Technical Impact: Gain Privileges or Assume Identity; Read Application Data; Read Files or Directories

An attacker may be able to access resources with the elevated privilege that could not be accessed with the attacker's original privileges. This is particularly likely in conjunction with another flaw, such as a buffer overflow.
+ Demonstrative Examples

Example 1

The following example demonstrates the weakness.

(bad code)
Example Language:
// Do some important stuff

// Do some non privileged stuff.
(bad code)
Example Language: Java 
method() {
AccessController.doPrivileged(new PrivilegedAction()) {
public Object run() {
// Insert all code here




Example 2

The following code calls chroot() to restrict the application to a subset of the filesystem below APP_HOME in order to prevent an attacker from using the program to gain unauthorized access to files located elsewhere. The code then opens a file specified by the user and processes the contents of the file.

(bad code)
Example Language:
FILE* data = fopen(argv[1], "r+");

Constraining the process inside the application's home directory before opening any files is a valuable security measure. However, the absence of a call to setuid() with some non-zero value means the application is continuing to operate with unnecessary root privileges. Any successful exploit carried out by an attacker against the application can now result in a privilege escalation attack because any malicious operations will be performed with the privileges of the superuser. If the application drops to the privilege level of a non-root user, the potential for damage is substantially reduced.

+ Potential Mitigations

Phases: Architecture and Design; Operation

Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.

Phase: Architecture and Design

Strategy: Separation of Privilege

Follow the principle of least privilege when assigning access rights to entities in a software system.

Phase: Architecture and Design

Strategy: Separation of Privilege

Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.

Ensure that appropriate compartmentalization is built into the system design and that the compartmentalization serves to allow for and further reinforce privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide when it is appropriate to use and to drop system privileges.

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

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:
  • Compare binary / bytecode to application permission manifest

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:
  • Host-based Vulnerability Scanners – Examine configuration for flaws, verifying that audit mechanisms work, ensure host configuration meets certain predefined criteria

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:
  • Manual Source Code Review (not inspections)
Cost effective for partial coverage:
  • Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:
  • Source code Weakness Analyzer
  • Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Automated Static Analysis

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:
  • Permission Manifest Analysis

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:
  • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)
  • Formal Methods / Correct-By-Construction
Cost effective for partial coverage:
  • Attack Modeling

Effectiveness: High

+ 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


CWE-271, CWE-272, and CWE-250 are all closely related and possibly overlapping. CWE-271 is probably better suited as a category.


If system privileges are not dropped when it is reasonable to do so, this is not a vulnerability by itself. According to the principle of least privilege, access should be allowed only when it is absolutely necessary to the function of a given system, and only for the minimal necessary amount of time. Any further allowance of privilege widens the window of time during which a successful exploitation of the system will provide an attacker with that same privilege. If at all possible, limit the allowance of system privilege to small, simple sections of code that may be called atomically.

When a program calls a privileged function, such as chroot(), it must first acquire root privilege. As soon as the privileged operation has completed, the program should drop root privilege and return to the privilege level of the invoking user.

+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
7 Pernicious KingdomsLeast Privilege Violation
CLASPFailure to drop privileges when reasonable
CERT C Secure CodingPOS02-CFollow the principle of least privilege
CERT Java Secure CodingSEC00-JDo not allow privileged blocks to leak sensitive information across a trust boundary
CERT Java Secure CodingSEC01-JDo not allow tainted variables in privileged blocks
Software Fault PatternsSFP36Privilege
+ Content History
Submission DateSubmitterOrganization
7 Pernicious Kingdoms
Modification DateModifierOrganization
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2008-10-14CWE Content TeamMITRE
updated Maintenance_Notes
2008-11-24CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings
2009-03-10CWE Content TeamMITRE
updated Demonstrative_Examples
2009-05-27CWE Content TeamMITRE
updated Demonstrative_Examples
2009-12-28CWE Content TeamMITRE
updated Potential_Mitigations
2010-06-21CWE Content TeamMITRE
updated Potential_Mitigations
2010-12-13CWE Content TeamMITRE
updated Other_Notes
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships, Taxonomy_Mappings
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-07-30CWE Content TeamMITRE
updated Detection_Factors, Taxonomy_Mappings
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Causal_Nature, Common_Consequences, Demonstrative_Examples, Modes_of_Introduction, Relationships

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Page Last Updated: January 18, 2018