PT-2021-23228 · Symfony · Symfony Httpkernel

Soner Sayakci · Published 2021-11-24 · Updated 2024-03-06 · CVE-2021-41267

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Name of the Vulnerable Software and Affected Versions Symfony/Http-Kernel versions 5.2 through 5.3.11

Description The issue arises from the accessibility of the X-Forwarded-Prefix header in sub-requests, even when it is not part of the "trusted headers" allowed list. This allows an attacker to forge requests containing the X-Forwarded-Prefix header, leading to a web cache poisoning issue. The vulnerability can be exploited when a Symfony application is running behind a proxy or a load-balancer.

Recommendations For Symfony/Http-Kernel versions 5.2 through 5.3.11, update to version 5.3.12 or later to ensure that the X-Forwarded-Prefix header is not forwarded to sub-requests when it is not trusted. As a temporary workaround, consider restricting access to the X-Forwarded-Prefix header in sub-requests to minimize the risk of exploitation.

Exploit

Fix

HTTP Request/Response Smuggling

Weakness Enumeration

CWE-444

Related Identifiers

BIT-SYMFONY-2021-41267

CVE-2021-41267

GHSA-Q3J3-W37X-HQ2Q

Affected Products

Symfony Httpkernel

References · 17

• 🔥 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2021-41267.yaml · Exploit
• 🔥 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2021-41267.yaml · Exploit
• https://github.com/symfony/symfony/security/advisories/GHSA-q3j3-w37x-hq2q · Patch
• https://github.com/symfony/symfony/pull/44243 · Patch
• https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487 · Patch
• https://osv.dev/vulnerability/BIT-symfony-2021-41267 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-41267 · Security Note
• https://osv.dev/vulnerability/GHSA-q3j3-w37x-hq2q · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-41267 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-41267 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-41267 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-41267 · Security Note
• https://github.com/symfony/symfony/releases/tag/v5.3.12 · Note
• https://t.me/cvenotify/23981 · Telegram Post
• https://t.me/cibsecurity/32974 · Telegram Post