Windows NT Slows Down Because of Land Attack (165005)
The information in this article applies to:
- Microsoft Windows NT Server 4.0 Terminal Server Edition
- Microsoft Windows NT Workstation 3.51
- Microsoft Windows NT Workstation 4.0
- Microsoft Windows NT Server 3.51
- Microsoft Windows NT Server 4.0
- Microsoft Windows NT Server, Enterprise Edition 4.0
This article was previously published under Q165005 SYMPTOMS
After receiving spoofed connection request (SYN) packets, Windows NT may
begin to operate slowly. After about one minute, Windows NT returns to
normal operation.
NOTE: This problem may occur with TCP/IP on other operating systems as
well.
CAUSE
This behavior occurs because of "Land Attack." Land Attack sends SYN
packets with the same source and destination IP addresses and the same
source and destination ports to a host computer. This makes it appear as if
the host computer sent the packet to itself. Windows NT operates more
slowly while the host computer tries to respond to itself.
RESOLUTION
Microsoft has updated Tcpip.sys to correct the problem. Instructions for
installing it are available from Microsoft support channels, or directly
from the Internet locations below.
NOTE: This hotfix was originally posted on November 26, 1997. A subsequent
fix was completed on January 9, 1998 to address another nearly identical
attack and this hotfix has replaced the original one. The original hotfix
is included in Windows NT 4.0 Service Pack 3. The most recent hotfix is
not; however, it is available from the following Internet locations:
Windows NT 4.0To 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.
NOTE: The above link is one path; it has been wrapped for readability.
NOTE: This fix supercedes the Land-fix, the ICMP-fix and the OOB-fix
hotfixes.
Windows NT 3.51
To resolve this problem in Windows NT 3.51, obtain the following fix or
wait for the next Windows NT service pack.
This fix should have the following time stamp:
01/14/98 12:04p 123,824 Tcpip.sys (Intel)
01/14/98 12:00p 216,848 Tcpip.sys (Alpha)
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.
Microsoft has confirmed this problem could result in some degree of
security vulnerability in Windows NT version 3.51. A fully supported fix is
now available, but it has not been fully regression tested and should only
be applied to systems determined to be at risk of attack. Please evaluate
your system's physical accessibility, network and Internet connectivity,
and other factors to determine the degree of risk to your system. If your
system is sufficiently at risk, Microsoft recommends you apply this fix.
Otherwise, wait for the next Windows NT service pack, which will contain
this fix. Please contact Microsoft Technical Support for more information.
| Modification Type: | Minor | Last Reviewed: | 9/23/2005 |
|---|
| Keywords: | kbHotfixServer kbQFE kbbug kbenv kbfix KB165005 |
|---|
|