macOS Command-Line Tools Retain Trust in eMudhra CAs With Recoverable Private Keys

macOS command-line tools reportedly remain vulnerable to forged TLS certificates because an outdated /etc/ssl/cert.pem trust bundle still trusts affected eMudhra certificate authorities, despite browser trust-store protections. eMudhra issued eight intermediate CA certificates whose private keys each came from just 256 possibilities, allowing attackers to recover them and forge certificates for arbitrary domains. Researcher Wayne discovered the weakness using Google’s open-source paranoid_crypto tool and reported it to root-store operators. Certificate Transparency logs showed no certificates issued by the affected intermediates, but that does not exclude exploitation against clients that do not enforce Certificate Transparency.

The remaining macOS exposure reportedly affects tools including git, curl, python3, and openssl. Apple provides a manual workaround, but installing macOS 27.2 reportedly reverses it, requiring administrators to reapply the remediation and verify trust settings after upgrading. Developer-beta users report that macOS 27.3 replaces the affected certificate bundle; its final release is expected no earlier than December. Certificate Transparency log operators have blocked the intermediates, and browser vendors deployed revocation protections, but inconsistent enforcement leaves some clients exposed. eMudhra subsequently exited the TLS certificate business, while Google expanded weak-key checks to all certificates recorded in the Common CA Database.