The following cyber advisory was issued by the New York State Office of Information Technology Services and is intended for State government entities. The information may or may not be applicable to the general public and, accordingly, the State does not warrant its use for any specific purposes.

ITS ADVISORY NUMBER:
2013-039

DATE(S) ISSUED:
4/09/2013

SUBJECT:
Vulnerability in MS Remote Desktop Client Could Allow Remote Code Execution (MS13-029)

OVERVIEW:

A vulnerability has been discovered in Microsoft Remote Desktop Client that could allow for remote code execution.  Remote desktop client is installed on Microsoft Windows operating systems by default, and is used to remotely log in to systems hosting the remote desktop service. Exploitation may occur if a user visits or is redirected to a web page which is specifically crafted to take advantage of the vulnerability. Successful exploitation of these vulnerabilities could result in the attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights.

SYSTEMS AFFECTED:

  • Windows XP with Remote Desktop Connection 6.1 and 7.0 Client
  • Windows XP Professional x64 with Remote Desktop Connection 6.1 Client
  • Windows Server 2003 with Remote Desktop Connection 6.1 Client
  • Windows Vista with Remote Desktop Connection 6.1 and 7.0 Client
  • Windows Server 2008 with Remote Desktop Connection 6.1 Client
  • Windows 7 with Remote Desktop Connection 7.0 Client
  • Windows Server 2008 R2 with Remote Desktop Connection 7.0 Client

RISK:
Government:

  • Large and medium government entities: High
  • Small government entities: High

Businesses:

  • Large and medium business entities: High
  • Small business entities: High

Home users: High

DESCRIPTION:
A vulnerability has been discovered in Microsoft Remote Desktop Client that could allow for remote code execution.  This vulnerability is caused when the Microsoft Remote Desktop ActiveX Control, mstscax.dll, attempts to access an object in memory that has been freed.  This access leads to the corruption of memory allowing execution of arbitrary code in the context of the current user.

Exploitation may occur if a user visits or is redirected to a web page which is specifically crafted to take advantage of the vulnerability. Successful exploitation of these vulnerabilities could result in the attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights

RECOMMENDATIONS:
We recommend the following actions be taken:

  • 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.

REFERENCES:
Microsoft:
http://technet.microsoft.com/en-us/security/bulletin/MS13-029

CVE:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-1296

Security Focus:
http://www.securityfocus.com/bid/58874

Deborah A. Snyder

Acting Chief Information Security Officer


 

Cyber Security

GIS