A stack-based buffer overflow vulnerability exists in the Palo Alto Networks GlobalProtect app that enables a man-in-the-middle attacker to disrupt system processes and potentially execute arbitrary code with SYSTEM privileges. This issue impacts: GlobalProtect app 5.1 versions earlier than GlobalProtect app 5.1.9 on Windows; GlobalProtect app 5.2 versions earlier than GlobalProtect app 5.2.8 on Windows; GlobalProtect app 5.2 versions earlier than GlobalProtect app 5.2.8 on the Universal Windows Platform; GlobalProtect app 5.3 versions earlier than GlobalProtect app 5.3.1 on Linux.