CVE-2023-29020
CSRF token fixation in fastify-passport
Impact
The [CSRF](https://owasp.org/www-community/attacks/csrf) protection enforced by the `@fastify/csrf-protection` library, when combined with `@fastify/passport`, can be bypassed by network and same-site attackers. ## Details `fastify/csrf-protection` implements the [synchronizer token pattern](https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#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](https://canitakeyoursubdomain.name/) 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. ## Fix As a solution, newer versions of `@fastify/passport` include the configuration options * `clearSessionOnLogin (default: true)` and * `clearSessionIgnoreFields (default: ['session'])` to clear all the session attributes by default, preserving those explicitly defined in `clearSessionIgnoreFields`. ## Credits * Pedro Adão (@pedromigueladao), [Instituto Superior Técnico, University of Lisbon](https://tecnico.ulisboa.pt/) * Marco Squarcina (@lavish), [Security & Privacy Research Unit, TU Wien](https://secpriv.wien/)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @fastify/passport | < 1.1.0 | 1.1.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Fastify | Passport | before 1.1.0 from 2.0.0 before 2.3.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- 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://github.com/advisories/GHSA-2ccf-ffrj-m4qw
- https://nvd.nist.gov/vuln/detail/CVE-2023-29020