Vulnerability in Microsoft Silverlight Could Allow For Security Feature Bypass (MS14-014)

ITS Advisory Number: 
2014-023
Date(s) Issued: 
Tuesday, March 11, 2014
Subject: 
Vulnerability in Microsoft Silverlight Could Allow For Security Feature Bypass (MS14-014)
Overview: 

A vulnerability has been discovered in the Microsoft Silverlight which could allow an attacker to take complete control of an affected system. Microsoft Silverlight is a web application framework that provides support for .NET applications and used for streaming media. The vulnerabilities can be exploited if a user visits or is redirected to a malicious web page, or runs a specially crafted Silverlight application.

Successful exploitation could result in an attacker gaining the ability to exploit vulnerabilities that were previously protected.  An attacker could tie this security feature bypass vulnerability to an additional vulnerability, most likely a remote code execution vulnerability. These vulnerabilities could then allow an attacker to gain 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
  • Microsoft Silverlight 5 Developer Runtime
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: 

A security feature bypass vulnerability has been discovered in Microsoft Silverlight due to improper implementation of Data Execution Protection (DEP) and Address Space Layout Randomization (ASLR). Successful exploitation could result in an attacker gaining the ability to exploit vulnerabilities that were previously protected.  An attacker could tie this security feature bypass vulnerability to an additional vulnerability, most likely a remote code execution vulnerability. These vulnerabilities could then allow an attacker to gain 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: 
  • Apply appropriate patches provided by Microsoft to vulnerable systems immediately after appropriate testing.
  • Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources.
  • Remind users not to open email attachments from unknown users or suspicious emails from trusted sources.
  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
References: 
Microsoft:
https://technet.microsoft.com/en-us/security/bulletin/ms14-014
CVE:
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0319