Flaw in Claude’s Chrome extension allowed ‘any’ other plugin to hijack victims’ AI

As businesses and governments turn to AI agents to access the internet and perform higher-level tasks, researchers continue to find serious flaws in large language models that can be exploited by bad actors.

The latest discovery comes from browser security firm LayerX, involving a bug in the Chrome extension for Anthropic’s Claude AI model that allows any other plugin – even ones without special permissions – to embed hidden instructions that can take over the agent. 

“The flaw stems from an instruction in the extension’s code that allows any script running in the origin browser to communicate with Claude’s LLM, but does not verify who is running the script,” wrote LayerX senior researcher Aviad Gispan. “As a result, any extension can invoke a content script (which does not require any special permissions) and issue commands to the Claude extension.”

Read more at CyberScoop