Security News > 2021 > September > Microsoft shares temp fix for ongoing Office 365 zero-day attacks

Microsoft today shared mitigation for a remote code execution vulnerability in Windows that is being exploited in targeted attacks against Office 365 and Office 2019 on Windows 10.

Microsoft is aware of targeted attacks that try to exploit the vulnerability by sending specially-crafted Microsoft Office documents to potential victims, the company says in an advisory today.

"An attacker could craft a malicious ActiveX control to be used by a Microsoft Office document that hosts the browser rendering engine. The attacker would then have to convince the user to open the malicious document" - Microsoft.

The attack is thwarted if Microsoft Office runs with the default configuration, where documents from the web are opened in Protected View mode or Application Guard for Office 365.

In a tweet today, EXPMON, who reported the security issue to Microsoft on Sunday, says that they found the vulnerability after detecting a "Highly sophisticated zero-day attack" aimed at Microsoft Office users.

EXPMON researchers reproduced the attack on the latest Office 2019 / Office 365 on Windows 10.

News URL

https://www.bleepingcomputer.com/news/security/microsoft-shares-temp-fix-for-ongoing-office-365-zero-day-attacks/