Using the compromised server as a jumping-off point to attack other parts of the internal network. How to Stay Protected
The attacker first authenticates to the vDesk portal as a low-privileged user (e.g., a support agent). The system creates a PHP session file containing the user's ID, call queue status, and telephony handles. vdesk hangupphp3 exploit
on GitHub for configuration examples involving host header validation and redirection. F5 DevCentral forum Using the compromised server as a jumping-off point
The exploit attempts to trigger a race condition by sending malformed SIP headers or HTTP POST payloads to the hangup.php3 endpoint during an active session termination. The goal is to force the backend process to retain a "zombie" thread while the frontend believes the session has ended. call queue status