CVE-2021-41267

Name	CVE-2021-41267
Description	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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
symfony (PTS)	jessie, jessie (lts)	2.3.21+dfsg-4+deb8u6	fixed
	stretch (security)	2.8.7+dfsg-1.3+deb9u3	fixed
	stretch (lts), stretch	2.8.7+dfsg-1.3+deb9u5	fixed
	buster (security), buster, buster (lts)	3.4.22+dfsg-2+deb10u3	fixed
	bullseye	4.4.19+dfsg-2+deb11u6	fixed
	bookworm	5.4.23+dfsg-1+deb12u2	fixed
	bookworm (security)	5.4.23+dfsg-1+deb12u4	fixed
	sid, trixie	6.4.16+dfsg-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
symfony	source	(unstable)	(not affected)

Notes

- symfony <not-affected> (Vulnerable code never in released version in unstable)
https://github.com/symfony/symfony/security/advisories/GHSA-q3j3-w37x-hq2q
https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487 (v5.3.12)