Cyberhaven is a data loss prevention (DLP) solution that helps companies protect their sensitive data from leaving their control. The company's browser extension, which has over 500,000 users, was found to have a vulnerability that allowed attackers to steal arbitrary cookies when the victim visited and clicked on a malicious website. This vulnerability was patched by Cyberhaven in version 24.9.3 of their extension, but it highlights the importance of treating all websites and their content as untrusted when developing browser extensions. The vulnerability exploited the fact that the extension's content script could send DOM events to the background script without checking whether they belonged to the currently loaded domain, allowing an attacker-controlled script to steal cookies from the victim's browser. Cyberhaven has since reworked its user identification mechanism to avoid exposing cookies to malicious scripts and restricted the cookie fetching functionality by only allowing certain pages to access their own cookies. The incident serves as a reminder of the need for security products to be treated with caution, as they often require elevated privileges to function effectively.