CVE-2021-29624 — fastify-csrf is an open-source plugin helps developers protect their Fastify ser

fastify-csrf is an open-source plugin helps developers protect their Fastify server against CSRF attacks. Versions of fastify-csrf prior to 3.1.0 have a "double submit" mechanism using cookies with an application deployed across multiple subdomains, e.g. "heroku&qu

01What is this vulnerability?

fastify-csrf is an open-source plugin helps developers protect their Fastify server against CSRF attacks. Versions of fastify-csrf prior to 3.1.0 have a "double submit" mechanism using cookies with an application deployed across multiple subdomains, e.g. "heroku"-style platform as a service. Version 3.1.0 of the fastify-csrf fixes it. the vulnerability. The user of the module would need to supply…

02Affected products

Vendor	Product	Versions
fastify	fastify	csrf — < 3.1.0

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

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2021-05-19T21:15:28.000Z
• Last modified: 2024-08-03T22:11:06.350Z

09References

• github.com — https://github.com/fastify/fastify-csrf/security/advisories/GHSA-rc4q-9m69-gqp8
• github.com — https://github.com/fastify/csrf/pull/2
• github.com — https://github.com/fastify/fastify-csrf/pull/51
• cheatsheetseries.owasp.org — https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Preven…
• github.com — https://github.com/fastify/fastify-csrf/releases/tag/v3.1.0
• owasp.org — https://owasp.org/www-pdf-archive/David_Johansson-Double_Defeat_of_Double-Submit…