This article was previously published under Q302755
This article has been archived. It is offered "as is" and will no longer be updated.
A vulnerability exists in the Windows 2000 SMTP service that could enable an unauthorized user to conduct mail relaying by using a Windows 2000 server. This could enable an attacker to disguise the origination point of an e-mail message, or co-opt a server's resources for mass mailings. The vulnerability is subject to the following constraints:
It would only affect servers that are running the native Windows 2000 Mail service. Mail servers that are running Microsoft Exchange (even on Windows 2000) would not be affected.
Even a computer that has the native Windows 2000 Mail service installed would only be affected if it were configured as a stand-alone computer rather than a member of a domain.
Proper use of a firewall could be used to prevent Internet users from exploiting the vulnerability.
This vulnerability results because of an authentication error in the SMTP service that installs as part of Microsoft Internet Information Services (IIS). In the case where the server is a stand-alone computer rather than a domain member, it could be possible for an unauthorized user to authenticate to the computer and use it for mail relaying.
To resolve this problem, either obtain the hotfix referenced in this section or Windows 2000 Security Rollup Package 1 (SRP1). For additional information about SRP1, click the following article number to view the article in the Microsoft Knowledge Base:
311401 Windows 2000 Security Rollup Package 1 (SR about SRP1), January 2002
To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
260910 How to obtain the latest Windows 2000 service pack
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.
The English version of this fix should have the following file attributes or later:
Date Time Version Size File name -------------------------------------------------------- 6/25/2001 08:13p 5.0.2195.3712 320,784 Aqueue.dll 6/25/2001 08:13p 5.0.2195.3712 66,832 Mailmsg.dll 6/25/2001 08:13p 5.0.2195.3649 38,160 Ntfsdrv.dll 6/25/2001 08:13p 5.0.2195.3779 434,448 Smtpsvc.dll
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Windows 2000. This problem was first corrected in Windows 2000 Service Pack 3.
For more information about this vulnerability, please see the following Microsoft Web site: