OWASSRF Exploitation Attempt Using Public POC - Webserver

Detects exploitation attempts of the OWASSRF vulnerability targeting Microsoft Exchange servers using publicly available Proof-of-Concept (POC) code. This rule specifically looks for requests to the OWA endpoint attempting to access the PowerShell backend endpoint, characterized by a specific user agent, POST method, successful status code (200), and URI query containing both '/owa/mastermailbox' and '/powershell'. This indicates an attempt to leverage the vulnerability for remote code execution.