Microsoft 365 Copilot ASCII Smuggling Data Exfiltration
Date: 2024-08
Affected: Microsoft 365 Copilot
Attack vector: data-exfiltration
Category: research
Severity: High

Rehberger disclosed a chain combining prompt injection, automatic tool invocation, ASCII smuggling using invisible Unicode tag characters, and link rendering to exfiltrate emails (including MFA codes) from M365 Copilot. Fixed by Microsoft.


Mitigations:

Architectural layers (MAESTRO):