Information Disclosure Vulnerability in Microsoft 365 Copilot

Microsoft has disclosed a security vulnerability (CVE-2024-38148) affecting Microsoft 365 Copilot. The vulnerability allows a remote, unauthenticated attacker to exploit the service and gain unauthorized access to sensitive information. This flaw resides within the cloud-based processing environment of the Copilot service. Because this is a SaaS-based vulnerability, the scope is limited to the Microsoft 365 Copilot infrastructure rather than on-premises hardware. Organizations relying on Copilot for data synthesis across their M365 tenant should assess the potential impact of data leakage, as the flaw enables an attacker to bypass intended access controls during information retrieval queries.

Impact

The vulnerability poses a risk of unauthorized data exposure for any organization using Microsoft 365 Copilot. If exploited, an attacker could potentially retrieve sensitive enterprise data processed by the AI service, leading to loss of confidentiality regarding internal documents, emails, or chat history accessible via the Copilot interface.

Recommendation

• Monitor the Microsoft 365 Message Center for official patch status and specific configuration guidance related to CVE-2024-38148.
• Review tenant access control policies for M365 Copilot to ensure the principle of least privilege is enforced for data sources integrated with the service.
• Apply all vendor-recommended service updates as soon as they are made available via the Microsoft 365 service management portal.