Secunia

A vulnerability has been reported in the Linux Kernel, which can be exploited by malicious people to cause a DoS (Denial of Service).

The vulnerability is caused due to the way the kernel handles caching of routing information. By flooding a Linux system with packets with spoofed source addresses, the handling of the cache will consume large amounts of CPU resources.

This can potentially bring a Linux system offline with a rate of only 400 packets/second by using carefully chosen source addresses that causes hash collisions in the table.

A DoS can still be performed, if the system uses iptables (netfilter) to filter traffic. This is even possible with randomly chosen IP addresses that don't cause a hash collision, since it just requires a higher rate of packets.

For further details about how this feature back-fired, see "Other References".

Solution
The vulnerability has reportedly been fixed in one of the latest versions.
Further details available in Customer Area

Provided and/or discovered by
Florian Weimer

Changelog
Further details available in Customer Area

Original Advisory
http://marc.theaimsgroup.com/?l=linux-kernel&m=104956079213417
http://rhn.redhat.com/errata/RHSA-2003-172.html

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area