Vulnerabilities in Microsoft Exchange Server Could Allow Remote Code Execution (MS13-105)

ITS Advisory Number: 
2013-121
Date(s) Issued: 
Tuesday, December 10, 2013
Subject: 
Vulnerabilities in Microsoft Exchange Server Could Allow Remote Code Execution (MS13-105)
Overview: 

Multiple vulnerabilities have been discovered in Microsoft Exchange Server that could allow remote code execution. Microsoft Exchange provides email, calendar, and contacts for corporate environments.  Exploitation of these vulnerabilities could occur by an attacker sending an email message containing a specially content to an affected Exchange server. Successful exploitation could result in the attacker gaining the same user rights as the LocalService account or the logged on user. Depending on the privileges associated with the account, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Systems Affected: 
  • Microsoft Exchange Server 2007
  • Microsoft Exchange Server 2010
  • Microsoft Exchange Server 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: 
N/A
Description: 

Multiple vulnerabilities have been discovered in Microsoft Exchange Server that could allow remote code execution. Two of the vulnerabilities exist in the WebReady Document Viewing feature. Two other vulnerabilities are caused by the Exchange Server not properly validating input. Exploitation of these vulnerabilities could be caused by an attacker sending specially crafted content to the Exchange Server or as an email attachment.  Successful exploitation could result in the attacker gaining the same user rights as the LocalService account or the logged on user. Depending on the privileges associated with the account, 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.
  • Evaluate the relative need for WebReady Document viewing and disable if deemed non-essential.
  • 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:
https://technet.microsoft.com/en-us/security/bulletin/ms13-105
CVE:
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-5763
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-5791
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-1330
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-5072