Vulnerability in symfony/security-bundle (CVE-2021-41268)
Summary
Vulnerability in symfony/security-bundle (CVE-2021-41268). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 5.3.12 or later.
Original description
The description as published by the source.
Symfony/SecurityBundle is the security system for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Since the rework of the Remember me cookie in version 5.3.0, the cookie is not invalidated when the user changes their password. Attackers can therefore maintain their access to the account even if the password is changed as long as they have had the chance to login once and get a valid remember me cookie. Starting with version 5.3.12, Symfony makes the password part of the signature by default. In that way, when the password changes, then the cookie is not valid anymore.
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-2021-41268 has been found in symfony/security-bundle.
Successful exploitation can lead to full system takeover.
What to do: upgrade symfony/security-bundle to 5.3.12 or later.
If unsure, ask your IT team or search "symfony/security-bundle CVE-2021-41268" on the vendor's site.
CVE-2021-41268 (symfony/security-bundle) — CWE-384
Attack vector: remote (network-reachable) / no user interaction
Patched: 5.3.12 — 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-384) exists in symfony/security-bundle.
Check the vendor advisory for the affected versions of symfony/security-bundle.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 5.3.12.
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 'symfony/security-bundle' . 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 'symfony/security-bundle' . | 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
symfony/security-bundle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 symfony/security-bundle to 5.3.12ステージング環境で 5.3.12 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
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- patch github.com
- web github.com
- web github.com
- web symfony.com