pac4j-jwt versions prior to 4.5.9, 5.7.9, and 6.3.3 contain an authentication bypass vulnerability in JwtAuthenticator when processing encrypted JWTs that allows remote attackers to forge authentication tokens. Attackers who possess the server's RSA public key can create a JWE-wrapped PlainJWT with arbitrary subject and role claims, bypassing signature verification to authenticate as any user including administrators.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy 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
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 3
https://www.codeant.ai/security-research/pac4j-jwt-authentication-bypass-public…
disclosure@vulncheck.com
https://www.pac4j.org/blog/security-advisory-pac4j-jwt-jwtauthenticator.html
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/pac4j-jwt-jwtauthenticator-authentication-…
disclosure@vulncheck.com