Microsoft Windows Media Services Remote Denial of Service Vulnerability



Date Discovered

March 9, 2004


It has been reported that Microsoft Windows Media Services is prone to a remote denial of service vulnerability. This may allow an attacker to cause the services to effectively deny access to legitimate users by sending specially crafted TCP/IP packets on TCP ports 7007 and/or 7778. Microsoft Windows Media Services 4.1 included with Microsoft Windows 2000 Server Service Pack 2, Service Pack 3, and Service Pack 4 is reported to be vulnerable to this issue. Windows Media Services 4.1 for Windows NT 4.0 is not vulnerable.

Technologies Affected

  • Microsoft Windows Media Services 4.1


Block external access at the network boundary, unless external parties require service.
If media streams are not used over TCP, blocking TCP ports 7007 and 7778 at the network router or firewall will mitigate against attacks.

Modify default configuration files to disable any unwanted behavior.
Windows Media Services may be configured to offer Windows Media Unicast Services only, however, this may have adverse affects on the functionality of Windows Media Services.

Microsoft has released a security bulletin MSO4-008 including fixes to address this issue. For Windows 2000 Server, this security update requires Service Pack 2 (SP2), Service Pack 3 (SP3), or Service Pack 4 (SP4):



Discovery is credited to Qualys <>.

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