A now-patched security flaw in the Microsoft Edge web browser could have been abused to install arbitrary extensions on users' systems and carry out malicious actions. "This flaw could have allowed an attacker to exploit a private API, initially intended for marketing purposes, to covertly install additional browser extensions with broad permissions without the user's knowledge," Guardio Labs security researcher Oleg Zaytsev said in a new report shared with The Hacker News. Tracked as CVE-2024-21388 (CVSS score: 6.5), it was addressed by Microsoft in Edge stable version 121.0.2277.83 released on January 25, 2024, following responsible disclosure in November 2023. The Windows maker credited both Zaytsev and Jun Kokatsu for reporting the issue. "An attacker who successfully exploited this vulnerability could gain the privileges needed to install an extension," Microsoft said in an advisory for the flaw, adding it "could lead to a browser sandbox escape." Describing it as a privilege escalation flaw, the tech giant also emphasized that a successful exploitation of the bug requires an attacker to "take additional actions prior to exploitation to prepare the target environment." According to Guardio's findings, CVE-2024-21388 allows a bad actor with the ability to run JavaScript on bing[.]com or microsoft[.]com pages to install any extensions from the Edge Add-ons store sans requiring user's consent or interaction. This is made possible by the fact that the browser comes with…Read More