CVE-2025-52565

Description

A flaw was found in runc. CVE-2025-52565 is very similar in concept and application toCVE-2025-31133, except that it exploits a flaw in /dev/console bind-mounts. When creating the /dev/console bind-mount (to /dev/pts/$n), if an attacker replaces /dev/pts/$n with a symlink then runc will bind-mount the symlink target over /dev/console.

Statement

Red Hat considers this as an Important flaw since the impact is limited to local attack with minimal privileges in order to jeopardize the environment.

Mitigation

Potential mitigations for this issue include:

* Using user namespaces, with the host root user not mapped into the container's namespace. procfs file permissions are managed using Unix DAC and thus user namespaces stop a container process from being able to write to them.
* Not running as a root user in the container (this includes disabling setuid binaries with noNewPrivileges). As above, procfs file permissions are managed using Unix DAC and thus non-root users cannot write to them.
* The default SELinux policy should mitigate this issue, as the /dev/console bind-mount does not re-label the mount and so the container process should not be able to write to unsafe procfs files. However, CVE-2025-52881 allows an attacker to bypass LSM labels, and so this mitigation is not helpful when considered in combination with CVE-2025-52881.
* The default AppArmor profile used by most runtimes will NOT help mitigate this issue, as /dev/console access is permitted. You could create a custom profile that blocks access to /dev/console, but such a profile might break regular containers. In addition, CVE-2025-52881 allows an attacker to bypass LSM labels, and so that mitigation is not helpful when considered in combination with CVE-2025-52881.

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 Score8.27.5N/A
Attack VectorLocalLocalN/A
Attack ComplexityLowHighN/A
Privileges RequiredLowLowN/A
User InteractionRequiredRequiredN/A
ScopeChangedChangedN/A
ConfidentialityHighHighN/A
Integrity ImpactHighHighN/A
Availability ImpactHighHighN/A

Vector

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

NVD: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H

Understanding the Weakness (CWE)

Confidentiality,Integrity,Access Control

Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism

An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.

Other

Technical Impact: Execute Unauthorized Code or Commands

Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.

Frequently Asked Questions

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