A high-severity SSRF vulnerability in Microsoft 365 Copilot Business Chat enables authenticated attackers to perform unauthorized network requests and escalate their privileges within the environment.

This vulnerability involves a Server-Side Request Forgery (SSRF) flaw where an authorized user can manipulate the application into making unauthorized requests to internal or external resources. This can be leveraged to bypass network security controls and achieve privilege escalation.

Successful exploitation allows an attacker to interact with internal services that are not intended to be public-facing. This can lead to the exposure of sensitive internal data, lateral movement within the Microsoft 365 environment, and elevated access to corporate resources. The CVSS score of 8.9 reflects the significant risk to network security and data confidentiality.

Immediate Action: Apply the security updates provided by Microsoft immediately. Administrators should refer to the official Microsoft Security Response Center (MSRC) advisory for specific deployment instructions.

Proactive Monitoring: Monitor network traffic for unusual outbound requests originating from the Copilot service and review audit logs for unauthorized privilege escalation attempts.

Compensating Controls: Implement strict egress filtering and network segmentation to limit the ability of the Copilot service to reach sensitive internal endpoints.

Public Exploit Available: false

Due to the integration of Microsoft 365 Copilot with sensitive corporate data, this high-severity SSRF must be addressed urgently. Organizations should prioritize the application of Microsoft's security patches to prevent potential privilege escalation and unauthorized internal network access.