Users have always found browser extensions to be a useful tool for increasing productivity and streamlining tasks. They have, however, become a prime target for malicious actors attempting to exploit flaws, impacting both individual users and companies.
Despite efforts to boost security, several of these extensions have found ways to exploit vulnerabilities in Google's latest extension framework, Manifest V3 (MV3). SquareX's recent research explained how these rogue extensions can continue to evade crucial security protections, exposing millions of users to risks such as data theft, malware, and unauthorised access to sensitive information.
Google has always had troubles with Chrome addons. In June 2023, the company had to manually remove 32 vulnerable extensions that had been installed 72 million times before being removed.
Google's previous extension framework, Manifest Version 2 (MV2), was notoriously unstable. It frequently granted excessive rights to extensions and allowed scripts to be introduced without user knowledge, making it less complicated for cybercriminals to steal data, access sensitive information, and install malware.
In response, Google launched Manifest V3, which intended to improve security by limiting permissions and requiring extensions to declare their scripts in advance. While MV3 was supposed to address the vulnerabilities found in MV2, SquareX's study indicates that it falls short in important areas.
Malicious extensions built on MV3 can still circumvent security measures and grab live video streams from collaboration services such as Google Meet and Zoom Web without requiring specific permission. They can even add unauthorised contributors to private GitHub repositories and send users to phishing pages masquerading as password managers.
Furthermore, these malicious extensions, like their MV2 counterparts, can access browser history, cookies, bookmarks, and download history by displaying a fake software update pop-up that dupes users into downloading the malware.
Once the malicious extension is installed, individuals and businesses are unable to notice its activity, leaving them vulnerable. Endpoint protection, Secure Access Service Edge (SASE), and Secure Web Gateways (SWG) are examples of security solutions that cannot dynamically assess potential risks in browser extensions.
SquareX has created a number of solutions targeted at enhancing browser extension security in order to address these issues. Their strategy includes customised rules that let administrators choose which extensions to accept or ban depending on user ratings, reviews, update history, and extension permissions.
This system can prevent network requests from extensions in real time using policies, machine learning insights, and heuristic analysis. Additionally, SquareX is experimenting with dynamic analysis of Chrome extensions using a customised Chromium browser on its cloud server, which will provide greater insights into the behaviour of potentially malicious extensions.
