A remote code execution vulnerability exists in Microsoft Office software when it fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could use a specially crafted file to perform actions in the security context of the current user. For example, the file could then take actions on behalf of the logged-on user with the same permissions as the current user. To exploit the vulnerability, a user must open a specially crafted file with an affected version of Microsoft Office software. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) that contains a specially crafted file that is designed to exploit the vulnerability. However, an attacker would have no way to force the user to visit the website. Instead, an attacker would have to convince the user to click a link, typically by way of an enticement in an email or Instant Messenger message, and then convince the user to open the specially crafted file. The security update addresses the vulnerability by correcting how Microsoft Office handles files in memory.
Is the Preview Pane an attack vector for this vulnerability? No, the Preview Pane is not an attack vector. Are the updates for the Microsoft Office for Mac currently available? The security update for Microsoft Office 2016 for Mac and Microsoft Office 2019 for Mac are not immediately available. The updates will be released as soon as possible, and when they are available, customers will be notified via a revision to this CVE information.
Menahem Breuer and Ariel Koren of <a href="https://www.mimecast.com/blog/">Mimecast Research Labs</a>