Ghidra < 12.1 - Authentication Bypass via Null Signature in PKIAuthenticationModule

Ghidra before 12.1 contains an authentication bypass vulnerability in PKIAuthenticationModule.authenticate() that allows any user with a valid CA-signed certificate to impersonate other users by presenting their public certificate with a null signature. Attackers can escalate privileges, modify repository access controls, exfiltrate shared reverse engineering databases, and permanently compromise server integrity.