Vulnerability in cloud-init
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 DEBIAN-CVE-2021-3429 has been found in cloud-init.
Confidential information can be exposed externally.
What to do: upgrade cloud-init to 20.4.1-2 or later.
If unsure, ask your IT team or search "cloud-init DEBIAN-CVE-2021-3429" on the vendor's site.
DEBIAN-CVE-2021-3429 (cloud-init)
Attack vector: local / no user interaction
Patched: 20.4.1-2 — 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 cloud-init.
Check the vendor advisory for the affected versions of cloud-init.
Severity: ?. Confidential information can be exposed externally.
Update to 20.4.1-2.
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 'cloud-init' . 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 exposureidentify
grep -r 'cloud-init' . | 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
cloud-init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 patchpatch
Upgrade cloud-init to 20.4.1-2ステージング環境で 20.4.1-2 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 verificationverify
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
| Ecosystem | Package | Affected | Fixed |
|---|---|---|---|
| Debian:12 | cloud-init |
< 20.4.1-2 |
20.4.1-2 |
| Debian:13 | cloud-init |
< 20.4.1-2 |
20.4.1-2 |
| Debian:14 | cloud-init |
< 20.4.1-2 |
20.4.1-2 |
Original description The description as published by the source.
When instructing cloud-init to set a random password for a new user account, versions before 21.2 would write that password to the world-readable log file /var/log/cloud-init-output.log. This could allow a local user to log in as another user.
Source: OSV.dev (Open Source Vulnerabilities) OSV
References
- advisory security-tracker.debian.org