Microsoft announced that it is investigating reports of a new zero-day remote-code execution vulnerability that affects Windows, using Office docs. This flaw within MSHTML uses “specially-crafted” Microsoft Office documents to launch a targeted attack against the operating system.
Attackers can craft malicious ActiveX control to be used by a doc that hosts the browser rendering engine, thus allowing the bad actor to gain access when the user opens an infected file.
“Users whose accounts are configured to have fewer user rights on the system,” Microsoft noted, “could be less impacted than users who operate with administrative user rights.”
Microsoft noted that Defender Antivirus and Defender for Endpoint – detection build 1.349.22.0 or newer – each provide detection and protection for the vulnerability, and thus customers should keep their anti-malware software updated. The software company also reported that it may provide additional security updates via its monthly release process or an out-of-cycle security update.