Local Privilege Escalation in servereye client (sensorhub)

Summary

The servereye client (also known as sensorhub, technically ClientAgentContainerService) versions 20.15 and earlier are vulnerable to Local Privilege Escalation. The high-privileged service SE3Recovery (EmergencyRecoveryService.exe), running as SYSTEM, periodically monitors the directory %ProgramData%\ServerEye3\update\ for a trigger file named "update_available". Due to insufficient access restrictions on this directory, a local standard user can create the trigger file and provide a path to a directory containing malicious JSON instructions. The service subsequently executes the utility UpdaterAction.exe with SYSTEM privileges, which parses the instructions and performs an unvalidated file copy from a user-controlled source to a protected system destination (e.g., overwriting a service binary). This leads to full system compromise as the service automatically restarts the overwritten binary with SYSTEM privileges.