Secunia

Some vulnerabilities have been reported in Microsoft Windows, which can be exploited by malicious people to cause a DoS (Denial of Service) or compromise a vulnerable system.

1) Insufficient validation of IP options can be exploited to cause a vulnerable system to stop responding and restart or may allow execution of arbitrary code by sending a specially crafted IP packet to a vulnerable system.

NOTE: Most routers do reportedly not forward the malformed IP packets.

2) Errors within the handling of certain ICMP messages can be exploited to reset existing TCP connections or reduce the throughput.

For more information:
SA14904

3) An error within the handling of certain TCP packets can be exploited to reset established TCP connections on a vulnerable system.

For more information:
SA11440

4) Improper handling of IP packets with the same destination and source IP and the SYN flag set can be exploited to cause a system to consume all available CPU resources for a certain period of time.

This kind of attack was first reported in 1997 and became known as LAND attacks.

NOTE: This vulnerability is reportedly still present in the IPv6 handling with the below patches applied.

Solution
Apply patches.
Further details available in Customer Area

Provided and/or discovered by
1) Song Liu, Hongzhen Zhou, and Neel Mehta of ISS X-Force.
2) Fernando Gont and Qualys
4) Dejan Levaja

Changelog
Further details available in Customer Area

Original Advisory
MS05-019 (KB893066):
http://www.microsoft.com/technet/security/Bulletin/MS05-019.mspx

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area