Exploitation of CVE-2023-29357 SharePoint Vulnerability

CVE-2023-29357 is a critical Microsoft SharePoint Server Privilege Escalation Vulnerability. Microsoft patched the vulnerability as part of their June 2023 Patch Tuesday updates. The vulnerability is being actively exploited in the wild. Successful exploitation allows threat actors to gain administrator privileges. Threat actors exploit the vulnerability with no user interaction by sending spoofed JSON Web Token (JWT) authentication tokens to a vulnerable SharePoint Server to bypass the authentication and grant access to the authenticated user privileges. The concern is the potential of combining the CVE-2023-29357 vulnerability with the CVE-2023-24955 a Remote Code Execution (RCE) vulnerability (CVSS score: 7.2) which allows the impersonation of the authenticated users leading to arbitrary code execution within the SharePoint server.