Vulnerability in tar (ALPINE-CVE-2021-32804)

Summary

vulnerability in tar (ALPINE-CVE-2021-32804). Data can be tampered with by attackers. Exploitable via ``preservePaths``.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **ALPINE-CVE-2021-32804** has been found in tar. Attackers can target a specific entry point like ``preservePaths`` over the network to misuse the product. Data can be tampered with by attackers. CVSS score: ?/10. What to do: apply the vendor's official patched release. If unsure, ask your IT team or search "tar ALPINE-CVE-2021-32804" on the vendor's site.

ALPINE-CVE-2021-32804 (tar) — Attack vector: remote (network-reachable) / unauthenticated Attack surface: `preservePaths` / `true` / `onentry` / `entry.path` 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 tar. Attackers reach the vulnerable code path via ``preservePaths`` without authentication.

📍 Affected scope

tar — . Attack surface: `preservePaths` / `true` / `onentry` / `entry.path`.

🔥 Severity

Severity: ?. Data can be tampered with by attackers

🔧 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 'tar' .` 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

1
Identify exposure identify
```
grep -r 'tar' . | 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 `tar` を grep し、稼働しているサービス・バージョンを把握する。
7
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 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。