Mobatek MobaXterm 12.1 contains a structured exception handling (SEH) based buffer overflow vulnerability in the username field of session files that allows remote attackers to execute arbitrary code. Attackers can craft a malicious MobaXterm sessions file with overflow data that triggers the vulnerability when imported and executed, enabling reverse shell execution with user privileges.

A vulnerability has been found in Mobatek MobaXterm Home Edition up to 26.1. This affects an unknown part in the library msimg32.dll. The manipulation leads to uncontrolled search path. An attack has to be approached locally. The attack is considered to have high complexity. It is indicated that the exploitability is difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 26.2 is able to mitigate this issue. It is suggested to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

MobaXterm versions prior to 26.1 contain an uncontrolled search path element vulnerability. The application calls WinExec to execute Notepad++ without a fully qualified executable path when opening remote files. An attacker can exploit the search path behavior by placing a malicious executable earlier in the search order, resulting in arbitrary code execution in the context of the affected user.

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.