Laravel Socialite's Facebook provider contains an authentication bypass vulnerability that allows unauthenticated attackers to replay captured OIDC id_tokens by exploiting the missing nonce claim validation in the getUserByOIDCToken() function within FacebookProvider.php. Attackers who obtain a valid, unexpired id_token issued for the same Facebook App ID can submit the captured token to the backend userFromToken() endpoint, bypassing authentication controls because signature, aud, and iss checks pass while no session-bound nonce comparison is performed, resulting in unauthorized access to victim accounts.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/laravel/socialite
disclosure@vulncheck.com
https://github.com/laravel/socialite/commit/caf714f55d51ab0d914b40033d8b0f489d6…
disclosure@vulncheck.com
https://github.com/laravel/socialite/pull/789
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/laravel-socialite-facebook-provider-authen…
disclosure@vulncheck.com