CVE-2023-27495 – Bypass of CSRF protection in the presence of predictable userInfo in @fastify/csrf-protection

https://notcve.org/view.php?id=CVE-2023-27495

@fastify/csrf-protection is a plugin which helps protect Fastify servers against CSRF attacks. The CSRF protection enforced by the @fastify/csrf-protection library in combination with @fastify/cookie can be bypassed from network and same-site attackers under certain conditions. @fastify/csrf-protection supports an optional userInfo parameter that binds the CSRF token to the user. This parameter has been introduced to prevent cookie-tossing attacks as a fix for CVE-2021-29624. Whenever userInfo parameter is missing, or its value can be predicted for the target user account, network and same-site attackers can 1. fixate a _csrf cookie in the victim's browser, and 2. forge CSRF tokens that are valid for the victim's session. • https://github.com/fastify/csrf-protection/commit/be3e5761f37aa05c7c1ac8ed44499c51ecec8058 https://github.com/fastify/csrf-protection/security/advisories/GHSA-qrgf-9gpc-vrxw https://www.cvedetails.com/cve/CVE-2021-29624 • CWE-352: Cross-Site Request Forgery (CSRF) •