Microsoft Office for Mac 14.5.8 Patches Mac Spoofing Vulnerability

Microsoft has released Office for Mac 14.5.8 with security patches for two memory corruption flaws and a Mac spoofing vulnerability. The most severe of the vulnerabilities "could allow remote code execution if a user opens a specially crafted Office file," said Microsoft in its security bulletin (MS15-116).

This update applies to the following Microsoft software: Office 2011, Office 2011 Home and Business Edition, Word 2011, Excel 2011, PowerPoint 2011, Outlook 2011, Office for Mac Standard 2011 Edition, Microsoft Office for Mac Home & Student 2011, and Microsoft Office for Mac Academic 2011.

The Office for Mac update addresses three security bugs altogether — two of which are related to remote code execution (memory corruption vulnerabilities) and the other related to spoofing. Microsoft summarized the Mac spoofing bug in its security bulletin:

For [the Mac spoofing vulnerability] to be exploited, a user must preview a maliciously crafted email from an attacker where they would unknowingly be redirected to a malicious URL. [In turn], the malicious website could spoof content or be used as a pivot to chain an attack with other vulnerabilities in web services. [...] At the time this security bulletin was originally issued, Microsoft is unaware of any attack attempting to exploit this vulnerability.

Details of the vulnerabilities patched in this update are as follows:

Microsoft addressed the memory corruption vulnerabilities by correcting how Office handles objects in memory. Additionally, Microsoft addressed the Mac spoofing vulnerability by correcting how Microsoft Outlook validates and sanitizes HTML input.

Office for Mac 2011 14.5.8 can be downloaded and installed using the Microsoft AutoUpdate application for Mac, or you can visit the Microsoft Download Center to get the Office for Mac 14.5.8 update (113.4 MB).