CVE-2020-5255
Description
In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 4.4.8-1 |
| sid | Fixed | 4.4.8-1 |
| forky | Fixed | 4.4.8-1 |
| bullseye | Fixed | 4.4.8-1 |
| bookworm | Fixed | 4.4.8-1 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Packagist | symfony/http-foundation | >=4.4.0,<4.4.7 | 4.4.7 |
| Packagist | symfony/http-foundation | >=5.0.0,<5.0.7 | 5.0.7 |
| Packagist | symfony/symfony | >=4.4.0,<4.4.7 | 4.4.7 |
| Packagist | symfony/symfony | >=5.0.0,<5.0.7 | 5.0.7 |
References
- https://github.com/symfony/symfony/security/advisories/GHSA-mcx4-f5f5-4859
- https://nvd.nist.gov/vuln/detail/CVE-2020-5255
- https://github.com/symfony/symfony/commit/dca343442e6a954f96a2609e7b4e9c21ed6d74e6
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-foundation/CVE-2020-5255.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2020-5255.yaml
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/C36JLPHUPKDFAX6D5WYFC4ALO2K7RDUQ
- https://symfony.com/blog/cve-2020-5255-prevent-cache-poisoning-via-a-response-content-type-header
- https://symfony.com/cve-2020-5255
- https://security-tracker.debian.org/tracker/CVE-2020-5255
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.