Ultimate PHP Board (UPB) 1.9.6 and earlier uses a cryptographically weak block cipher with a large key collision space, which allows remote…

Ultimate PHP Board (UPB) 1.9.6 and earlier uses a cryptographically weak block cipher with a large key collision space, which allows remote attackers to determine a suitable decryption key given the plaintext and ciphertext by obtaining the plaintext password, which is sent when logging in, and the ciphertext, which is set in the pass_env cookie.