Description: Fernando Gont has published an Internet-Draft describing how ICMP (Internet Control Message Protocol) can be exploited by malicious people to cause a DoS (Denial of Service). Cisco has acknowledged that various Cisco products are affected.
The published Internet-Draft details three types of attacks, which utilize the following ICMP messages to cause a negative impact on TCP connections either terminating or originating from a vulnerable device.
1) ICMP "hard" error messages
2) ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages (known as PMTUD attacks)
3) ICMP "source quench" messages
These attacks can all be exploited to cause TCP connection resets, reduce the throughput in existing TCP connections, or consume large amounts of CPU and memory resources.
Successful exploitation requires knowledge of IP address information of the source and destination of the TCP network connection..
NOTE: See the original advisory for a list of affected versions.
If you have new information regarding this Secunia advisory or a product in our database, please send it to us using either our web form or email us at vuln@secunia.com.
Ideas, suggestions, and other feedback are most welcome.
