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Microsoft Windows vulnerable to DoS via LAND attack

Vulnerability Note VU#396645

Original Release Date: 2005-04-13 | Last Revised: 2005-04-13


A vulnerability in Microsoft Windows may allow a remote attacker to cause a denial of service.


Microsoft Windows XP SP2 and Windows Server 2003 are vulnerable to a denial-of-service attack via a crafted TCP packet. The packet is spoofed in a manner such that the source and destination IP addresses are the same, the source and destination ports are the same, and the SYN flag is set. This type of attack is known as a LAND attack.

Upon receiving such a packet, Windows may become unresponsive for several seconds.


By sending a specially crafted TCP packet to a Windows machine, an attacker could cause excessive CPU usage on the target system. Repeated exploitation of this vulnerability could result in a sustained denial-of-service condition.


Apply a patch
Apply a patch as described in Microsoft Security Bulletin MS05-019.

Filter Network Traffic

Network firewall, Intrusion Detection and Prevention Systems, and packet filtering technology may be able to detect and block LAND attacks. If a perimeter network device is configured to drop incoming packets with source IP addresses that match addresses within the network, a remote attacker may not be able to exploit this vulnerability.

Vendor Information


Microsoft Corporation Affected

Notified:  March 09, 2005 Updated: March 23, 2005



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector



This vulnerability was publicly disclosed by Dejan Levaja.

This document was written by Will Dormann.

Other Information

CVE IDs: CVE-2005-0688
Severity Metric: 12.15
Date Public: 2005-03-05
Date First Published: 2005-04-13
Date Last Updated: 2005-04-13 17:20 UTC
Document Revision: 22

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