Vulnerability in libarchive (ALPINE-CVE-2021-31566)
Summary
Vulnerability in libarchive (ALPINE-CVE-2021-31566). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 3.5.3-r0 or later.
Original description
The description as published by the source.
An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to gain more privileges in a system.
Source: OSV.dev (Open Source Vulnerabilities) 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 ALPINE-CVE-2021-31566 has been found in libarchive.
Successful exploitation can lead to full system takeover.
What to do: upgrade libarchive to 3.5.3-r0 or later.
If unsure, ask your IT team or search "libarchive ALPINE-CVE-2021-31566" on the vendor's site.
ALPINE-CVE-2021-31566 (libarchive)
Attack vector: local / unauthenticated
Patched: 3.5.3-r0 — 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.
A vulnerability (unclassified) exists in libarchive.
Check the vendor advisory for the affected versions of libarchive.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 3.5.3-r0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'libarchive' . 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
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1Identify exposure identify
grep -r 'libarchive' . | 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
libarchiveを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade libarchive to 3.5.3-r0ステージング環境で 3.5.3-r0 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。
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3Post-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
References
- advisory security.alpinelinux.org