CVE-2023-29020

Description

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/)

How to fix CVE-2023-29020

To remediate CVE-2023-29020, upgrade the affected package to a fixed version below.

• —upgrade to 1.1.0 or later

Is CVE-2023-29020 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (1)

• from 0, < 1.1.0