Microsoft Patch Tuesday fixes a zero-day and 61 other vulnerabilities

While Adobe didn't have anything to fix on its Patch Tuesday, Microsoft rolled out patches to fix a total of 62 security bugs in its broad range of software applications.

The most important update this month addresses a zero-day remote code execution bug in Word 2007 and later releases, Word Automation Services, and Microsoft Office Web Apps Server. This bug is being exploited in the wild so the installation of this update is critical.

A remote code execution vulnerability exists in Microsoft Office software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.

Exploitation of the vulnerability requires that a user 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) containing a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file.

The full list of all the updates can be read at Bleeping Computer. The site notes there are two more bugs on the list that were publicly disclosed, but those aren't abused yet in live attacks. One of these bugs affects Windows Subsystem for Linux, while the other impacts Microsoft Office SharePoint.