The vulnerability existed in the password storage of Mobateks MobaXterm below 25.0.
MobaXTerm uses an initialization vector (IV) that is generated by encrypting null bytes with a derivate of the users master key. As both the master key is static, and AES ECB produces the same output with the same input the IV for AES CFB is always the same.The static IV makes it easier to obtain sensitive information and decrypt data if the data is stored at rest.

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.