Security Update for Microsoft Office (MS16-099)

ITS Advisory Number: 
2016-132
Date(s) Issued: 
Tuesday, August 9, 2016
Subject: 
Security Update for Microsoft Office (MS16-099)
Overview: 

Multiple vulnerabilities have been discovered in Microsoft Office, the most severe of which could result in remote code execution if the user opens a specifically crafted Microsoft Office file. Successful exploitation of these vulnerabilities could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, 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 those who operate with administrative user rights.

Systems Affected: 
  • Microsoft Office 2007, 2010, 2013, 2013 RT, 2016
  • Microsoft Office for Mac 2011
  • Microsoft Office 2016 for Mac
  • Microsoft Word Viewer
RISK
GOVERNMENT
Large and medium government entities: 
High
Small government entities: 
Medium
BUSINESS
Large and medium business entities: 
High
Small business entities: 
Medium
Home Users: 
Low
Description: 

Multiple vulnerabilities have been discovered in Microsoft Office, the most severe of which could allow for remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited these vulnerabilities could run arbitrary code in the context of the current user.

 

  • Four memory corruption vulnerabilities exist when Microsoft Office fails to properly handle objects in memory. (CVE-2016-3313, CVE-2016-3316, CVE-2016-3317, CVE-2016-3318)
  • One information disclosure vulnerability exists when Microsoft Office OneNote improperly discloses its memory contents. (CVE-2016-3315)

 

Successful exploitation of these vulnerabilities could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, 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 those who operate with administrative user rights.

Actions: 
  • After appropriate testing, apply appropriate patches provided by Microsoft to vulnerable systems.
  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
  • Apply the principle of Least Privilege to all systems and services.
  • Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources.
  • Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources.
  • Apply the principle of Least Privilege to all systems and services.