Peter Winter-Smith of NGSSoftware has discovered a low risk vulnerability in Active Directory which can allow an unauthenticated user to cause a denial of service condition on any affected system. The only affected platform is Windows 2000 with Active Directory. Windows 2003 Server is NOT affected by this issue. The vulnerability occurs when Active Directory attempts to parse an LDAP request containing the ASN.1 type 0x08. As soon as this type is encountered, the hosting system reaches a 100% CPU usage condition from which it does not seem to recover. Making multiple such requests will render the system completely unresponsive. This issue has been fixed in the Microsoft bulletin MS07-039, which can be found at: http://www.microsoft.com/technet/security/Bulletin/MS07-039.mspx NGSSoftware Insight Security Research http://www.ngssoftware.com/ http://www.databasesecurity.com/ http://www.nextgenss.com/ +44(0)208 401 0070 -- E-MAIL DISCLAIMER The information contained in this email and any subsequent correspondence is private, is solely for the intended recipient(s) and may contain confidential or privileged information. For those other than the intended recipient(s), any disclosure, copying, distribution, or any other action taken, or omitted to be taken, in reliance on such information is prohibited and may be unlawful. If you are not the intended recipient and have received this message in error, please inform the sender and delete this mail and any attachments. The views expressed in this email do not necessarily reflect NGS policy. NGS accepts no liability or responsibility for any onward transmission or use of emails and attachments having left the NGS domain. NGS and NGSSoftware are trading names of Next Generation Security Software Ltd. Registered office address: 52 Throwley Way, Sutton, SM1 4BF with Company Number 04225835 and VAT Number 783096402
