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.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6180
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-018
http://www.vupen.com/english/advisories/2009/1537
http://www.us-cert.gov/cas/techalerts/TA09-160A.html
http://www.securitytracker.com/id?1022349
http://www.securityfocus.com/bid/35226
http://support.avaya.com/elmodocs2/security/ASA-2009-214.htm
http://secunia.com/advisories/35355
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=804