Open Redirect in github.com/authelia/authelia/v4 (CVE-2021-29456)
Summary
Vulnerability in github.com/authelia/authelia/v4 (CVE-2021-29456). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 4.28.0 or later.
Original description
The description as published by the source.
Authelia is an open-source authentication and authorization server providing 2-factor authentication and single sign-on (SSO) for your applications via a web portal. In versions 4.27.4 and earlier, utilizing a HTTP query parameter an attacker is able to redirect users from the web application to any domain, including potentially malicious sites. This security issue does not directly impact the security of the web application itself. As a workaround, one can use a reverse proxy to strip the query parameter from the affected endpoint. There is a patch for version 4.28.0.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory 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 CVE-2021-29456 has been found in github.com/authelia/authelia/v4.
Risk of unauthorized operations or information disclosure.
What to do: upgrade github.com/authelia/authelia/v4 to 4.28.0 or later.
If unsure, ask your IT team or search "github.com/authelia/authelia/v4 CVE-2021-29456" on the vendor's site.
CVE-2021-29456 (github.com/authelia/authelia/v4) — CWE-601
Attack vector: remote (network-reachable)
Patched: 4.28.0 — 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 (CWE-601) exists in github.com/authelia/authelia/v4.
Check the vendor advisory for the affected versions of github.com/authelia/authelia/v4.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 4.28.0.
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 'github.com/authelia/authelia/v4' . 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
-
1Identify exposure identify
grep -r 'github.com/authelia/authelia/v4' . | 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
github.com/authelia/authelia/v4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 github.com/authelia/authelia/v4 to 4.28.0ステージング環境で 4.28.0 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。
-
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 nvd.nist.gov
- package github.com
- patch github.com