CVE-2023-27495 — @fastify/csrf-protection is a plugin which helps protect Fastify servers against

@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. @

01What is this vulnerability?

@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…

02Affected products

Vendor	Product	Versions
fastify	csrf	protection — < 4.1.0, >= 5.0.0, < 6.3.0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

08Timeline

• Published: 2023-04-20T17:05:21.515Z
• Last modified: 2025-02-05T16:07:38.884Z

09References

• github.com — https://github.com/fastify/csrf-protection/security/advisories/GHSA-qrgf-9gpc-vr…
• github.com — https://github.com/fastify/csrf-protection/commit/be3e5761f37aa05c7c1ac8ed44499c…
• www.cvedetails.com — https://www.cvedetails.com/cve/CVE-2021-29624