CVE-2009-1138: Microsoft Windows 2000

High severity, CVSS 10.0. EPSS: 39.4% chance of exploitation in the next 30 days.

The LDAP service in Active Directory on Microsoft Windows 2000 SP4 does not properly free memory for LDAP and LDAPS requests, which allows remote attackers to execute arbitrary code via a request that uses hexadecimal encoding, whose associated memory is not released, related to a "DN AttributeValue," aka "Active Directory Invalid Free Vulnerability." NOTE: this issue is probably a memory leak.

Affected products

• Microsoft Windows 2000: any version

Published 2009-06-10. Last modified 2026-06-16.