IOS IPSec PMTUD attack?

[j.beckner]

Cisco Security Advisory: Crafted ICMP Messages Can Cause Denial of Service

Document ID: 64520

Revision 1.1

Last Updated 2005 April 12 1800 UTC (GMT)

http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml

I just finished reading and analyzing the above security advisory. Has anyone actually seen this vulnrerabilty expoited in the field?

[b.hsu]

As per the RFC,http://www.watersprings.org/pub/id/draft-gont-tcpm-icmp-attacks-03.txt these attacks were known for quite some time by the researchers. But they were considered unfeasible. They beleve its feasible now.