Microsoft discloses workaround for severe zero-day flaw in Office

Microsoft has released mitigations for a zero-day vulnerability in Office that could enable execution of code by a remote user.

The flaw, which security researcher Kevin Beaumont dubbed "Follina," affects the Microsoft Support Diagnostic Tool (MSDT) in Windows and has reportedly been exploited.

The vulnerability affects the majority of versions of Windows in use today — including Windows 7 and above, as well as Windows Server 2008 and above.

In a blog post, Microsoft provided a workaround for the remote code execution flaw, which "exists when MSDT is called using the URL protocol from a calling application such as Word."

"An attacker who successfully exploits this vulnerability can run arbitrary code with the privileges of the calling application," Microsoft said in its post. "The attacker can then install programs, view, change, or delete data, or create new accounts in the context allowed by the user’s rights."

The vulnerability is being tracked as CVE-2022-30190. Microsoft has ascribed a "high" severity level to the vulnerability with a score of 7.8 out of 10.