Python GnuPG 0.4.3 Improper Input Validation

Researchers discovered a way to inject data through the passphrase property of the gnupg.GPG.encrypt() and gnupg.GPG.decrypt() methods when symmetric encryption is used. The supplied passphrase is not validated for newlines, and the library passes --passphrase-fd=0 to the gpg executable, which expects the passphrase on the first line of stdin, and the ciphertext to be decrypted or plaintext to be encrypted on subsequent lines. By supplying a passphrase containing a newline an attacker can control/modify the ciphertext/plaintext being decrypted/encrypted. Proof of concept exploit included. Version 0.4.3 is affected.