The vulnerability exists in the password storage of Mobateks MobaXterm in versions below 25.0. MobaXTerm uses an initialisation vector (IV) consisting only of zero bytes and a master key to encrypt each password individually. In the default configuration, on opening MobaXTerm, the user is prompted for their password.

A derivative of the password is used as the master key. As both the master key and the IV are the same for each stored password, the AES CFB ciphertext depends only on the plaintext (the password). The static IV and master key make it easier to obtain sensitive information and to decrypt data when it is stored at rest.