Vulnerability in Kernel (CVE-2025-21656)

Summary

Vulnerability in Kernel (CVE-2025-21656). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.6.72, 6.12.10 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (drivetemp) Fix driver producing garbage data when SCSI errors occur

scsi_execute_cmd() function can return both negative (linux codes) and
positive (scsi_cmnd result field) error codes.

Currently the driver just passes error codes of scsi_execute_cmd() to
hwmon core, which is incorrect because hwmon only checks for negative
error codes. This leads to hwmon reporting uninitialized data to
userspace in case of SCSI errors (for example if the disk drive was
disconnected).

This patch checks scsi_execute_cmd() output and returns -EIO if it's
error code is positive.

[groeck: Avoid inline variable declaration for portability]

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-21656 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.6.72, 6.12.10 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21656" on the vendor's site.

CVE-2025-21656 (Kernel)
Patched: 6.6.72, 6.12.10 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.6.72, 6.12.10.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.6.72, 6.12.10
```
ステージング環境で 6.6.72, 6.12.10 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"5.6.0"},{"fixed":"6.6.72"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.10"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21656 linux-lts
Debian DEBIAN-CVE-2025-21656 linux
Ubuntu UBUNTU-CVE-2025-21656 linux-hwe-edge