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CVE-2021-41556
critical
CVSS 10.0
Out-of-Bounds Read in cpp (CVE-2021-41556)
Summary
vulnerability in cpp (CVE-2021-41556). Successful exploitation can lead to full system takeover.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2021-41556** has been found in cpp.
Successful exploitation can lead to full system takeover. CVSS score: 10.0/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "cpp CVE-2021-41556" on the vendor's site.
CVE-2021-41556 (cpp) — CWE-125 / CVSS v3 10.0
Attack vector: remote (network-reachable) / unauthenticated / 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
**out-of-bounds read** (CWE-125) exists in cpp.
📍 Affected scope
cpp — .
🔥 Severity
Severity: Critical (CVSS 10.0/10). 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 'cpp' .` 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 'cpp' . | 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 `cpp` 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
- exploit af854a3a-2127-422b-91ae-364da2661108
- web http://www.squirrel-lang.org/#download
- web https://github.com/albertodemichelis/squirrel/commit/23a0620658714b996d20da3d4dd1a0dcf9b0bd98
- web af854a3a-2127-422b-91ae-364da2661108
- web af854a3a-2127-422b-91ae-364da2661108
- web 134c704f-9b21-4f2e-91b3-4a467353bcc0
- web https://nvd.nist.gov/vuln/detail/CVE-2021-41556
- web https://blog.sonarsource.com/squirrel-vm-sandbox-escape
- web https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BV7SJJ44AGAX4ILIVPREIXPJ2GOG3FKV
- web https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M3FQILX7UUEERSDPMZP3MKGTMY2E7ESU
- web https://lists.fedoraproject.org/archives/list/[email protected]/message/BV7SJJ44AGAX4ILIVPREIXPJ2GOG3FKV
- web https://lists.fedoraproject.org/archives/list/[email protected]/message/M3FQILX7UUEERSDPMZP3MKGTMY2E7ESU
- web https://www.sonarsource.com/blog/squirrel-vm-sandbox-escape
- web https://github.com/advisories/GHSA-cm28-mc8h-9h49