← Back
CVE-2025-21761
high
CVSS 7.8
Use-After-Free in linux (CVE-2025-21761)
Summary
vulnerability in linux (CVE-2025-21761). Successful exploitation can lead to full system takeover.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2025-21761** has been found in linux.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "linux CVE-2025-21761" on the vendor's site.
CVE-2025-21761 (linux) — CWE-416 / CVSS v3 7.8
Attack vector: local / no user interaction
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
**use-after-free** (CWE-416) exists in linux.
📍 Affected scope
linux — .
🔥 Severity
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover
🔧 How to fix
Update to the patched release per vendor advisory.
🛡️ 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 'linux' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'linux' . | 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 `linux` を grep し、稼働しているサービス・バージョンを把握する。
-
7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
References
- web https://git.kernel.org/stable/c/5828937742af74666192835d657095d95c53dbd0
- web https://git.kernel.org/stable/c/7e01abc34e87abd091e619161a20f54ed4e3e2da
- web https://git.kernel.org/stable/c/8ec57509c36c8b9a23e50b7858dda0c520a2d074
- web https://git.kernel.org/stable/c/90b2f49a502fa71090d9f4fe29a2f51fe5dff76d
- web https://git.kernel.org/stable/c/a849a10de5e04d798f7f286a2f1ca174719a617a
- web https://git.kernel.org/stable/c/a8816b3f1f151373fd30f1996f00480126c8bb11
- web https://git.kernel.org/stable/c/a884f57600e463f69d7b279c4598b865260b62a1
- web https://git.kernel.org/stable/c/e85a25d1a9985645e796039e843d1de581d2de1e
- web https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
- web https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- web https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- web https://nvd.nist.gov/vuln/detail/CVE-2025-21761
- web https://github.com/advisories/GHSA-q6cq-g5qv-hwc8