EchoLeak – 0-Click AI Vulnerability Enabling Data Exfiltration from 365 Copilot

Summary

Executive SummaryAim Labs has identified a critical zero-click AI vulnerability, dubbed “EchoLeak”, in Microsoft 365 (M365) Copilot and has disclosed several attack chains that allow an exploit of this vulnerability to Microsoft's MSRC team.This attack chain showcases a new exploitation technique we have termed "LLM Scope Violation" that may have additional manifestations in other RAG-based chatbots and AI agents. This represents a major research discovery advancement in how threat actors can attack AI agents - by leveraging internal model mechanics.The chains allow attackers to automatically exfiltrate sensitive and proprietary information from M365 Copilot context, without the user's awareness, or relying on any specific victim behavior. The result is achieved despite M365 Copilot's interface being open only to organization employees.To successfully perform an attack, an adversary simply needs to send an email to the victim without any restriction on the sender's email. As a zero-click AI vulnerability, EchoLeak opens up extensive opportunities for data exfiltration and extortion attacks for motivated threat actors. In an ever evolving agentic world, it showcases the potential risks that are inherent in the design of agents and chatbots.Aim Labs continues in its research activities to identify novel types of vulnerabilities associated with AI deployment and to develop guardrails that mitigate against such novel vulnerabilities.Aim Labs is not aware of any customers being impacted to date.TL;DRAim Security discovered “EchoLeak”, a vulnerability that exploits design flaws typical of RAG Copilots, allowing attackers to automatically exfiltrate any data from M365 Copilot’s context, without relying on specific user behavior. The primary chain is composed of three distinct vulnerabilities, but Aim Labs has identified additional vulnerabilities in its research process that may also enable an exploit.Attack FlowWhat is a RAG Copilot?M365 Copilot is a RAG-based chatbot tha...