Security Update for Microsoft Office to Address Remote Code Execution (MS16-029)

ITS Advisory Number: 
2016-045
Date(s) Issued: 
Tuesday, March 8, 2016
Subject: 
Security Update for Microsoft Office to Address Remote Code Execution (MS16-029)
Overview: 

This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. Customers 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: 
  • Office 2007, 2010, 2013, 2013 RT, 2016 

  • Office for Mac 2011, Office for Mac 2016

  • Word Viewer

  • SharePoint Server 2010, 2013

  • Office Web Apps 2010, 2013

RISK
GOVERNMENT
Large and medium government entities: 
High
Small government entities: 
High
BUSINESS
Large and medium business entities: 
High
Small business entities: 
High
Home Users: 
High
Description: 

Multiple remote code execution vulnerabilities exist in Microsoft Office software when the Office software fails to properly handle objects in memory.  An attacker who successfully exploited the vulnerabilities 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.  The vulnerabilities are as follows:

  • Microsoft Office Memory Corruption Vulnerability (CVE-2016-0021, CVE-2016-0134)

  • Microsoft Office Security Feature Bypass Vulnerability (CVE-2016-0057)

Exploitation of the vulnerabilities requires that a user open a specially crafted file with an affected version of Microsoft Office software. Note that the Preview Pane is not an attack vector for these vulnerabilities. In an email attack scenario an attacker could exploit the vulnerabilities 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 vulnerabilities. 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 Messenger message, and then convince them to open the specially crafted file.

Actions: 
  • Apply appropriate patches provided by Microsoft to vulnerable systems immediately after appropriate testing.

  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.

  • 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 untrusted sources.