One-click Microsoft 365 Copilot flaw exposed sensitive data

Researchers at Varonis Threat Labs have shown how a single malicious link could have let attackers quietly exfiltrate emails, calendar entries, indexed files and even multi-factor authentication codes from Microsoft 365 Copilot.

A chain of three overlooked bugs

The team chained three vulnerabilities—dubbed SearchLeak—into a seamless attack path. Because the lure was hosted on a genuine microsoft.com domain, standard anti-phishing filters and URL scanners failed to flag the threat. Once a user clicked, the attacker could request the Copilot Enterprise Search index, pull sensitive data, and relay it to an external server without raising alerts.

Why the fix matters

Microsoft has issued patches and updated its documentation. The episode highlights how generative-AI assistants that blend internal and web content can become inadvertent data leaks if their search back-ends are misconfigured or improperly scoped. Security teams are advised to review Copilot Enterprise Search permissions and audit any connectors that expose internal resources to AI queries.

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Source: The Hacker News. AI-assisted editorial synthesis — TechnoExpress.