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Case File

CVE-2023-29020

MEDIUM · CVSS 6.5 EPSS 0.38% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2023-04-21 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 6.5. Public exploit code or proof-of-concept references have been detected in its references.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2023-29020
Severity
MEDIUM
CVSS
6.5
EPSS
0.38%

Original NVD 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`.

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