Microsoft Windows Active Directory LDAP Request Validation Remote Denial Of Service Vulnerability



Date Discovered

July 10, 2007


Microsoft Windows is prone to a remote denial-of-service vulnerability because Microsoft Active Directory fails to handle specially crafted Lightweight Directory Access Protocol (LDAP) requests. An attacker can exploit this issue to cause the affected application to stop responding, denying further service to legitimate users.

Technologies Affected

  • Avaya CIE 1.0
  • Avaya CIE 1.0.2
  • Avaya Customer Interaction Express (CIE) Server 1.0
  • Avaya Customer Interaction Express (CIE) User Interface 1.0
  • Avaya Customer Interaction Express (CIE) User Interface 1.0.2
  • Avaya Messaging Application Server
  • Avaya Messaging Application Server MM 1.1
  • Avaya Messaging Application Server MM 2.0
  • Avaya Messaging Application Server MM 3.0
  • Avaya Messaging Application Server MM 3.1
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Server SP1
  • Microsoft Windows 2000 Server SP2
  • Microsoft Windows 2000 Server SP3
  • Microsoft Windows 2000 Server SP4


Block external access at the network boundary, unless external parties require service.
Restrict access to the affected computer at the network perimeter. Grant access for trusted hosts and networks only.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Use NIDS to monitor networks for anomalous activity and report attempted attacks. Audit logs regularly.

The vendor released patches to address this issue. Please see the references for more information. Microsoft security bulletin MS07-039 has been revised; please see the referenced bulletin for details.



Peter Winter-Smith of NGSSoftware is credited with the discovery of this vulnerability.

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