WebExtention Risk-Websites can steal browser data via extensions APIs

 Researcher finds nearly 200 Chrome, Firefox, and Opera extensions vulnerable to attacks from malicious sites.

Malicious websites can exploit browser extension APIs to execute code inside the browser and steal sensitive information such as bookmarks, browsing history, and even user cookies

The latter, an attacker can use to hijack a user's active login sessions and access sensitive accounts, such as email inboxes, social media profiles, or work-related accounts.

Furthermore, the same extension APIs can also be abused to trigger the download of malicious files and store them on the user device, and store and retrieve data in an extension's permanent storage, data that can later be used to track users across the web.

The French researcher says he was surprised by the results, as only 15 (7.61%) of the 197 extensions were developer tools, a category of extensions that usually have full control of what happens in a browser, and would have been the ones that he expected were easier to exploit

Around 55 percent of all the vulnerable extensions had fewer than 1,000 installs, but over 15 percent had over 10,000.