Szczegóły CWE-250

The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.

Sposoby wprowadzenia

Implementation
Installation
Architecture and Design
Operation

Odpowiednie platformy

Język

Class: Not Language-Specific (Undetermined)

Technologie

Class: Mobile (Undetermined)

Typowe konsekwencje

Zaobserwowane przykłady

Potencjalne środki zaradcze

Phases : Architecture and Design // Operation
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Phases : Architecture and Design
Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code [REF-76]. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting all possible communication channels that could interact with the privileged code, such as a secondary socket that is only intended to be accessed by administrators.
Phases : Architecture and Design
Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code [REF-76]. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting all possible communication channels that could interact with the privileged code, such as a secondary socket that is only intended to be accessed by administrators.
Phases : Implementation
Perform extensive input validation for any privileged code that must be exposed to the user and reject anything that does not fit your strict requirements.
Phases : Implementation
When dropping privileges, ensure that they have been dropped successfully to avoid CWE-273. As protection mechanisms in the environment get stronger, privilege-dropping calls may fail even if it seems like they would always succeed.
Phases : Implementation
If circumstances force you to run with extra privileges, then determine the minimum access level necessary. First identify the different permissions that the software and its users will need to perform their actions, such as file read and write permissions, network socket permissions, and so forth. Then explicitly allow those actions while denying all else [REF-76]. Perform extensive input validation and canonicalization to minimize the chances of introducing a separate vulnerability. This mitigation is much more prone to error than dropping the privileges in the first place.
Phases : Operation // System Configuration
Ensure that the software runs properly under the United States Government Configuration Baseline (USGCB) [REF-199] or an equivalent hardening configuration guide, which many organizations use to limit the attack surface and potential risk of deployed software.

Metody wykrywania

Manual Analysis

This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.

Black Box

Automated Static Analysis - Binary or Bytecode

Skuteczność : High

Manual Static Analysis - Binary or Bytecode

Skuteczność : SOAR Partial

Dynamic Analysis with Automated Results Interpretation

Skuteczność : SOAR Partial

Dynamic Analysis with Manual Results Interpretation

Skuteczność : SOAR Partial

Manual Static Analysis - Source Code

Skuteczność : High

Automated Static Analysis - Source Code

Skuteczność : SOAR Partial

Automated Static Analysis

Skuteczność : SOAR Partial

Architecture or Design Review

Skuteczność : High

Uwagi dotyczące mapowania podatności

Uzasadnienie : 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.
Komentarz : 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.

Powiązane wzorce ataków

Notatki

There is a close association with CWE-653 (Insufficient Separation of Privileges). CWE-653 is about providing separate components for each privilege; CWE-250 is about ensuring that each component has the least amount of privileges possible.
CWE-271, CWE-272, and CWE-250 are all closely related and possibly overlapping. CWE-271 is probably better suited as a category. Both CWE-272 and CWE-250 are in active use by the community. The "least privilege" phrase has multiple interpretations.
Privilege management functions can behave in some less-than-obvious ways, and they have different quirks on different platforms. These inconsistencies are particularly pronounced if you are transitioning from one non-root user to another.
Signal handlers and spawned processes run at the privilege of the owning process, so if a process is running as root when a signal fires or a sub-process is executed, the signal handler or sub-process will operate with root privileges.

Odniesienia

REF-6

Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors
Katrina Tsipenyuk, Brian Chess, Gary McGraw.
https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf

REF-196

The Protection of Information in Computer Systems
Jerome H. Saltzer, Michael D. Schroeder.
http://web.mit.edu/Saltzer/www/publications/protection/

REF-76

Least Privilege
Sean Barnum, Michael Gegick.
https://web.archive.org/web/20211209014121/https://www.cisa.gov/uscert/bsi/articles/knowledge/principles/least-privilege

REF-7

Writing Secure Code
Michael Howard, David LeBlanc.
https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223

REF-199

United States Government Configuration Baseline (USGCB)
NIST.
https://csrc.nist.gov/Projects/United-States-Government-Configuration-Baseline

REF-44

24 Deadly Sins of Software Security
Michael Howard, David LeBlanc, John Viega.

REF-62

The Art of Software Security Assessment
Mark Dowd, John McDonald, Justin Schuh.

REF-1479

State-of-the-Art Resources (SOAR) for Software Vulnerability Detection, Test, and Evaluation
Gregory Larsen, E. Kenneth Hong Fong, David A. Wheeler, Rama S. Moorthy.
https://www.ida.org/-/media/feature/publications/s/st/stateoftheart-resources-soar-for-software-vulnerability-detection-test-and-evaluation/p-5061.ashx

Zgłoszenie

Modyfikacje