Google Gemini Prompt Injection Flaw Exposed Private Calendar Data via Malicious Invites

Cybersecurity researchers have disclosed details of a security flaw that leverages indirect prompt injection targeting Google Gemini as a way to bypass authorization guardrails and use Google Calendar as a data extraction mechanism.

The vulnerability, Miggo Security’s Head of Research, Liad Eliyahu, said, made it possible to circumvent Google Calendar’s privacy controls by hiding a dormant malicious payload within a standard calendar invite.

“This bypass enabled unauthorized access to private meeting data and the creation of deceptive calendar events without any direct user interaction,” Eliyahu said in a report shared with The Hacker News.

The starting point of the attack chain is a new calendar event that’s crafted by the threat actor and sent to a target. The invite’s description embeds a natural language prompt that’s designed to do their bidding, resulting in a prompt injection.

The attack gets activated when a user asks Gemini a completely innocuous question about their…