CVE-2025-8941

Description

A flaw was found in linux-pam. The pam_namespace module may improperly handle user-controlled paths, allowing local users to exploit symlink attacks and race conditions to elevate their privileges to root. This CVE provides a "complete" fix for CVE-2025-6020.

Statement

This vulnerability in pam_namespace is rated Important because it allows a local, unprivileged user to escalate privileges to root by exploiting symlink attacks or race conditions in polyinstantiated directories under their control. Successful exploitation requires only the ability to create and manipulate filesystem paths in such directories, without the need for special capabilities or kernel-level vulnerabilities. In multi-user environments—such as shared systems, terminal servers, or certain container deployments, an unprotected or misconfigured pam_namespace configuration can serve as a single point of compromise. Privilege escalation flaws of this nature may also be chained with other vulnerabilities to maintain persistence or evade detection, further increasing the overall impact.

Mitigation

Disable the `pam_namespace` module if it is not essential for your environment, or carefully review and configure it to avoid operating on any directories or paths that can be influenced or controlled by unprivileged users, such as user home directories or world-writable locations like `/tmp`.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score7.8N/A7.8
Attack VectorLocalN/ALocal
Attack ComplexityLowN/ALow
Privileges RequiredLowN/ALow
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityHighN/AHigh
Integrity ImpactHighN/AHigh
Availability ImpactHighN/AHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Understanding the Weakness (CWE)

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 product from working at all and in the case of protection mechanisms such as authentication, it has the potential to lock out product users.

Frequently Asked Questions

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