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Microsoft Exchange Server Calendar Remote Code Execution Vulnerability


Date Discovered
5/9/2006 12:00:00 AM

Microsoft Exchange Server is prone to a vulnerability that may let attackers execute code remotely. This issue is exposed when the server handles emails that contain malicious calendar data that is included in meeting requests. If the issue is successfully exploited, this could completely compromise the computer hosting the mail server.

Symantec Enterprise Security Manager
Symantec Enterprise Security Manager posted an update to the OS Patch Policy that detects and reports systems that are not patched against this vulnerability. Click here for the advisory released May 11, 2006.

Symantec Vulnerability Assessment
Symantec Vulnerability Assessment detects and reports this vulnerability. Click here for the advisory released May 10, 2006.

Technologies Affected
Microsoft Exchange Server 2003 SP1
Microsoft Exchange Server 2003
Microsoft Exchange Server 2000
Microsoft Exchange Server 2000 SP1
Microsoft Exchange Server 2000 SP2
Microsoft Exchange Server 2003

Disallow anonymous access to services. Permit access for trusted individuals only.
If appropriate for the organization, require authentication for email clients. This will eliminate the risk of anonymous attacks, however, the server will still be vulnerable to attacks by authenticated users.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to requests that include NOP sleds and unexplained ingoing and outgoing traffic. This may indicate exploitation attempts or activity that results from successful exploitation.
Implement multiple redundant layers of security.
Memory protection schemes such as non-executable stack/heap configurations and randomly mapped memory segments may complicate exploitation of various code execution vulnerabilities.

Microsoft has released a security bulletin to address supported versions of Microsoft Exchange Server.
Microsoft Exchange Server 2000 :

Microsoft Patch Security Update for Exchange 2000 Server (KB916803)

Microsoft Exchange Server 2003 SP1:
Microsoft Patch Security Update for Exchange Server 2003 SP1 (KB916803)

Microsoft Exchange Server 2003 :
Microsoft Patch Security Update for Exchange Server 2003 SP2 (KB916803)

Source: Microsoft Security Bulletin MS06-019
URL: http://www.microsoft.com/technet/security/Bulletin/MS06-019.mspx

The discoverer of this issue is not known.

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