Avast! AntiVirus - X.509 Error Rendering Command Execution
Source: https://code.google.com/p/google-security-research/issues/detail?id=546 Avast will render the commonName of X.509 certificates into an HTMLLayout frame when your MITM proxy detects a bad signature. Unbelievably, this means CN="really?!?!?" actually works, and is pretty simple to convert...