Installing malware on your own computer with extra steps?
MCP enabled software gives you a list of options. If you check the Gmail one and the shell one you are instantly vulnerable to this kind of attack.
Common? Also, yes.
This one targets Claude. But we've already seen it with Copilot and I expect we'll soon see it hit Gemini, and others.
AI is being forcibly integrated across all major systems. Your email provider will set this up, if they haven't already.
I had assumed they weren't doing this precisely because of the enormous risk - if you have the ability to both read and send email you have all three legs of the lethal trifecta in one MCP!
So far, I have only seen unofficial MCPs for things like Gmail that work using their existing APIs.
https://windowsforum.com/threads/echoleak-cve-2025-32711-cri...
"At Microsoft, we believe in creating tools that empower you to work smarter and more efficiently. That’s why we’re thrilled to announce the first release of Model Context Protocol (MCP) support in Microsoft Copilot Studio. With MCP, you can easily add AI apps and agents into Copilot Studio with just a few clicks."
https://www.microsoft.com/en-us/microsoft-copilot/blog/copil...
That second link looks to me like an announcement of MCP client support, which means they get to outsource the really bad decisions to third-party MCP providers and users who select them.
Don't dismiss the root cause because the usecase is silly. The moment some user provided input reaches an LLM context, all bets are off. If you're running any local tools that provide shell access, then it's RCE, if you're running a browser / fetch tool that's data exfil, and so on.
The root cause is that LLMs receive both commands and data on the same shared channel. Until (if) this gets fixed, we're gonna see lots and lots of similar attacks.