Vulnerability in Microsoft Silverlight Could Allow for Remote Code Execution (MS16-109)

ITS Advisory Number: 
2016-152
Date(s) Issued: 
Tuesday, September 13, 2016
Subject: 
Vulnerability in Microsoft Silverlight Could Allow for Remote Code Execution (MS16-109)
Overview: 

A vulnerability has been discovered in Microsoft Silverlight, which could allow for remote code execution. Microsoft Silverlight is a media application for browsers on Microsoft Windows and Apple Mac OS technologies. Successful exploitation of this vulnerability 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.

Systems Affected: 
  • Microsoft Silverlight 5 prior to version 5.1.50709.0 for Windows Clients, Windows Servers, and Mac
  • Microsoft Silverlight 5 Developer Runtime prior to version 5.1.50709.0 for Windows Clients, Windows Servers, and Mac
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: 

One vulnerability has been discovered in Microsoft Silverlight, which could allow for remote code execution (CVE-2016-3367). This vulnerability exists when Microsoft Silverlight improperly allows applications to access objects in memory. To exploit the vulnerability, an attacker could host a website that contains a specially crafted Silverlight application and then convince a user to visit the compromised website, typically by enticing them to click a link in an email or instant message.

Successful exploitation 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.

Actions: 
  • After appropriate testing, apply update from Microsoft to vulnerable systems.
  • 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 un-trusted sources.