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Common Weakness Enumeration

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Home > CWE List > CWE-271: Privilege Dropping / Lowering Errors (4.16)  
ID

CWE-271: Privilege Dropping / Lowering Errors

Weakness ID: 271
Vulnerability Mapping: ALLOWED This CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review (with careful review of mapping notes)
Abstraction: 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.
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+ Description
The product does not drop privileges before passing control of a resource to an actor that does not have those privileges.
+ Extended Description
In some contexts, a system executing with elevated permissions will hand off a process/file/etc. to another process or user. If the privileges of an entity are not reduced, then elevated privileges are spread throughout a system and possibly to an attacker.
+ 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
Access Control

Technical Impact: Gain Privileges or Assume Identity

If privileges are not dropped, neither are access rights of the user. Often these rights can be prevented from being dropped.
Access Control
Non-Repudiation

Technical Impact: Gain Privileges or Assume Identity; Hide Activities

If privileges are not dropped, in some cases the system may record actions as the user which is being impersonated rather than the impersonator.
+ Potential Mitigations

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 the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

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

Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
+ 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 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. 269 Improper Privilege Management
ParentOf 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. 272 Least Privilege Violation
ParentOf 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. 273 Improper Check for Dropped Privileges
PeerOf 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. 274 Improper Handling of Insufficient Privileges
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 "Architectural Concepts" (CWE-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1011 Authorize Actors
+ 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
Architecture and Design
Implementation REALIZATION: This weakness is caused during implementation of an architectural security tactic.
Operation
+ 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)

+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

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:
chroot(APP_HOME);
chdir("/");
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.


+ Observed Examples
Reference Description
Program does not drop privileges after acquiring the raw socket.
Setuid program does not drop privileges after a parsing error occurs, then calls another program to handle the error.
Does not drop privileges in related groups when lowering privileges.
Does not drop privileges in related groups when lowering privileges.
Does not drop privileges before determining access to certain files.
Finger daemon does not drop privileges when executing programs on behalf of the user being fingered.
FTP server does not drop privileges if a connection is aborted during file transfer.
Program only uses seteuid to drop privileges.
Windows program running as SYSTEM does not drop privileges before executing other programs (many others like this, especially involving the Help facility).
Utility Manager launches winhlp32.exe while running with raised privileges, which allows local users to gain system privileges.
Setuid program does not drop privileges before executing program specified in an environment variable.
Setuid program does not drop privileges before processing file specified on command line.
Service on Windows does not drop privileges before using "view file" option, allowing code execution.
+ Weakness Ordinalities
Ordinality Description
Primary
(where the weakness exists independent of other weaknesses)
+ 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 ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 901 SFP Primary Cluster: Privilege
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1396 Comprehensive Categorization: Access Control
+ Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Abstraction

Rationale:

This CWE entry is a Class and might have Base-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit
+ Notes

Maintenance

CWE-271, CWE-272, and CWE-250 are all closely related and possibly overlapping. CWE-271 is probably better suited as a category.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER Privilege Dropping / Lowering Errors
+ References
[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 16: Executing Code With Too Much Privilege." Page 243. McGraw-Hill. 2010.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 9, "Dropping Privileges Permanently", Page 479. 1st Edition. Addison Wesley. 2006.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
PLOVER
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Description, Relationships, Taxonomy_Mappings, Weakness_Ordinalities
2008-10-14 CWE Content Team MITRE
updated Description, Maintenance_Notes
2009-12-28 CWE Content Team MITRE
updated Potential_Mitigations
2010-06-21 CWE Content Team MITRE
updated Potential_Mitigations
2011-03-29 CWE Content Team MITRE
updated Relationships
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Observed_Examples, References, Relationships
2012-10-30 CWE Content Team MITRE
updated Potential_Mitigations
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Causal_Nature, Modes_of_Introduction, Relationships
2020-02-24 CWE Content Team MITRE
updated Relationships
2020-12-10 CWE Content Team MITRE
updated Potential_Mitigations
2023-01-31 CWE Content Team MITRE
updated Description
2023-04-27 CWE Content Team MITRE
updated Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
Page Last Updated: November 19, 2024