Title: Microsoft Windows 2000 Domain Account Lockout Bypass Vulnerability
Severity: HIGH
Description:
Under certain circumstances, it is possible to bypass a domain account lockout policy on a local machine which would render this protective measure against brute force password attempts ineffective. The purpose of a domain account lockout policy is to disable an account after a certain number of unsuccessful login attempts. If this policy was not implemented, the password of a domain account could be guessed an unlimited number of times.
Windows 2000 hosts in a non-2000 domain using NTLM authentication will fail to recognize a domain account lockout policy for users whose credentials are locally cached. Cached credentials contain the username and password in hashed form and are used in the event that the domain controller is not available to perform authentication. Windows 2000 systems that are not using NTLM to perform authentication are not susceptible to this vulnerability, therefore clients that are members of Windows 2000 domains would not be vulnerable because Kerberos authentication is being implemented.
This vulnerability would allow for the possibility of successful retrieval of a valid password through the use of brute force techniques. If a malicious user was able to login with a password acquired from a brute force attack, they would gain privileges of the same level as the domain account but would be confined to the local machine because domain authentication would not be able to take place and the lockout policy would be exercised at the domain level.
Affected Products:
- Microsoft Windows 2000 Advanced Server SP1
- Microsoft Windows 2000 Professional SP1
- Microsoft Windows 2000 Server SP1
References:
Juniper Networks provides this content via a wide variety of sources and production methods. If notified of errors or omissions in the content of this page, Juniper Networks, at its discretion, will modify or remove the page or leave the content as is, depending on various factors including but not limited to the reputation and authority of the party providing the notification. Please use the contact information displayed elsewhere on this page to report any errors or omissions regarding the content on this page.
