Access Violation in Dns.exe Caused by Malicious Telnet Attack (169461)
The information in this article applies to:
- Microsoft Windows NT Server 4.0 Terminal Server Edition
- Microsoft Windows NT Server 4.0
This article was previously published under Q169461 SYMPTOMS
You may receive an Access Violation in Dns.exe. This is most often occurs
on computers connected to public networks, such as the Internet, where
deliberate attacks are common.
CAUSE
This particular attack is usually generated maliciously by typing the
following command on the attacking system:
telnet <mycomputer> 19 | telnet <mycomputer> 53
This command causes a telnet connection to be established to port 19 (the
chargen service, which generates a string of characters) with the output
redirected to a telnet connection to port 53 (the DNS service.) This flood
of characters causes an Access Violation in the DNS service, which is
terminated, disrupting name resolution services.
RESOLUTION
The Microsoft DNS Server has been modified to correct this problem.
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the
Microsoft Knowledge Base:
152734 How to Obtain the Latest Windows NT 4.0 Service Pack
For your convenience, the English version of this post-SP3 hotfix has been
posted to the following Internet location. However, Microsoft recommends
that you install Windows NT 4.0 Service Pack 4 to correct this problem.
STATUS
Microsoft has confirmed this problem could result in some degree of
security vulnerability in Windows NT version 4.0. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.
| Modification Type: | Major | Last Reviewed: | 6/24/2004 |
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| Keywords: | kbbug kbfix kbnetwork KB169461 |
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