CVE-2021-41267
Published: 24 November 2021
Symfony/Http-Kernel is the HTTP kernel component for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Headers that are not part of the "trusted_headers" allowed list are ignored and protect users from "Cache poisoning" attacks. In Symfony 5.2, maintainers added support for the `X-Forwarded-Prefix` headers, but this header was accessible in SubRequest, even if it was not part of the "trusted_headers" allowed list. An attacker could leverage this opportunity to forge requests containing a `X-Forwarded-Prefix` header, leading to a web cache poisoning issue. Versions 5.3.12 and later have a patch to ensure that the `X-Forwarded-Prefix` header is not forwarded to subrequests when it is not trusted.
Priority
Status
Package | Release | Status |
---|---|---|
symfony Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(code not present)
|
focal |
Not vulnerable
(code not present)
|
|
hirsute |
Ignored
(end of life)
|
|
impish |
Ignored
(end of life)
|
|
jammy |
Needed
|
|
kinetic |
Ignored
(end of life, was needed)
|
|
lunar |
Ignored
(end of life, was needed)
|
|
mantic |
Ignored
(end of life, was needed)
|
|
noble |
Needed
|
|
trusty |
Ignored
(end of standard support)
|
|
upstream |
Not vulnerable
(debian: Vulnerable code never in released version in unstable)
|
|
xenial |
Not vulnerable
(code not present)
|
|
Patches: upstream: https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487 |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 6.5 |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | Required |
Scope | Unchanged |
Confidentiality | None |
Integrity impact | High |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
References
- https://github.com/symfony/symfony/security/advisories/GHSA-q3j3-w37x-hq2q
- https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487 (v5.3.12)
- https://github.com/symfony/symfony/releases/tag/v5.3.12
- https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487
- https://github.com/symfony/symfony/pull/44243
- https://www.cve.org/CVERecord?id=CVE-2021-41267
- NVD
- Launchpad
- Debian