CVE-2025-21785

Description

From CVE.org

In the Linux kernel, the following vulnerability has been resolved: arm64: cacheinfo: Avoid out-of-bounds write to cacheinfo array The loop that detects/populates cache information already has a bounds check on the array size but does not account for cache levels with separate data/instructions cache. Fix this by incrementing the index for any populated leaf (instead of any populated level).

Statement

The bug actual only for ARM64 hardware (if ARMv8 or similar ARM CPU being used). There is no known way to trigger the bug, because user cannot control internal values for particular CPUs. As result would not be possible to trigger overflow by user even before this additional check added. For CVSS score the attack complexity is high as result.

Mitigation

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

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 Score77.87.8
Attack VectorLocalLocalLocal
Attack ComplexityHighLowLow
Privileges RequiredLowLowLow
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityHighHighHigh
Integrity ImpactHighHighHigh
Availability ImpactHighHighHigh

Vector

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

NVD: 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

Red Hat CVSS v3 Score Explanation

There is no known way to trigger the bug, because user cannot control internal values for particular ARM CPU. As result would not be possible to trigger overflow by regular user or the attack complexity would be very high.

Understanding the Weakness (CWE)

Integrity

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.

Availability

Technical Impact: DoS: Crash, Exit, or Restart

Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.

Other

Technical Impact: Unexpected State

Subsequent write operations can produce undefined or unexpected results.

Frequently Asked Questions

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