Microsoft MDAC Function Broadcast Response Buffer Overrun Vulnerability



Date Discovered

January 13, 2004


Microsoft has released an advisory reporting a buffer overrun vulnerability in an MDAC function. This issue is exposed when an application makes a broadcast request to query for SQL Servers on the network and malformed data is returned in the broadcast response. Successful exploitation will allow for code execution in the context of the application using the vulnerable MDAC function. If the application is run with system-level privileges, this could completely compromise a vulnerable system. Exploitation attempts may also result in a denial of service in client applications. Microsoft has reported that this would only result in a denial of service with MDAC 2.8.

Technologies Affected

  • Microsoft MDAC 2.5
  • Microsoft MDAC 2.5 RTM
  • Microsoft MDAC 2.5 SP1
  • Microsoft MDAC 2.5 SP2
  • Microsoft MDAC 2.5 SP3
  • Microsoft MDAC 2.6
  • Microsoft MDAC 2.6 RTM
  • Microsoft MDAC 2.6 SP1
  • Microsoft MDAC 2.6 SP2
  • Microsoft MDAC 2.6 SP2 Refresh
  • Microsoft MDAC 2.7
  • Microsoft MDAC 2.7 RTM Refresh
  • Microsoft MDAC 2.7 SP1
  • Microsoft MDAC 2.7 SP1 Refresh
  • Microsoft MDAC 2.8


Block external access at the network boundary, unless external parties require service.
Use network access controls to filter remote access to MDAC-related ports on client systems, including UDP port 1434. External/remote access to all systems that do not require it should also be filtered to limit exposure to this and other latent vulnerabilities.

Run all software as a nonprivileged user with minimal access rights.
Ensure that any applications that use MDAC are run with the least privileges required. This will limit the consequences of successful exploitation.

Microsoft has released updates to address this issue.



Announced by the vendor.

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