{"cve":"CVE-2023-29020","nvd":{"published":"2023-04-21T23:15:20.267","modified":"2026-06-17T05:49:12.297","status":"Modified","description":"@fastify/passport is a port of passport authentication library for the Fastify ecosystem. The CSRF (Cross-Site Request Forger) protection enforced by the `@fastify/csrf-protection` library, when combined with `@fastify/passport` in affected versions, can be bypassed by network and same-site attackers. `fastify/csrf-protection` implements the synchronizer token pattern (using plugins `@fastify/session` and `@fastify/secure-session`) by storing a random value used for CSRF token generation in the `_csrf` attribute of a user's session. The `@fastify/passport` library does not clear the session object upon authentication, preserving the `_csrf` attribute between pre-login and authenticated sessions. Consequently, CSRF tokens generated before authentication are still valid. Network and same-site attackers can thus obtain a CSRF token for their pre-session, fixate that pre-session in the victim's browser via cookie tossing, and then perform a CSRF attack after the victim authenticates. As a solution, newer versions of `@fastify/passport` include the configuration options: `clearSessionOnLogin (default: true)` and `clearSessionIgnoreFields (default: ['passport', 'session'])` to clear all the session attributes by default, preserving those explicitly defined in `clearSessionIgnoreFields`.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-352","CWE-384"],"references":["https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#synchronizer-token-pattern","https://github.com/fastify/fastify-passport/commit/07c90feab9cba0dd4779e47cfb0717a7e2f01d3d","https://github.com/fastify/fastify-passport/security/advisories/GHSA-2ccf-ffrj-m4qw","https://owasp.org/www-community/attacks/csrf","https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#synchronizer-token-pattern"],"products":["fastify:passport"],"source":"nvd","synced_at":"2026-10-19T21:38:05.473481323+00:00"},"epss":{"cve":"CVE-2023-29020","score":0.00384,"percentile":0.32473,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-2ccf-ffrj-m4qw","url":"https://osv.dev/vulnerability/GHSA-2ccf-ffrj-m4qw","summary":"CSRF token fixation in fastify-passport","modified":"2026-09-10T03:49:53.189759641Z","packages":[{"ecosystem":"npm","name":"@fastify/passport","purl":"pkg:npm/%40fastify/passport","ranges":["<1.1.0"],"fixed":["1.1.0"]},{"ecosystem":"npm","name":"@fastify/passport","purl":"pkg:npm/%40fastify/passport","ranges":[">=2.0.0 <2.3.0"],"fixed":["2.3.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}