CVE-2001-0323

The CVE-2001-0323 entry describes a denial-of-service risk in the ICMP path MTU (PMTU) discovery feature used by various UNIX systems. The underlying issue is that remote attackers can spoof ICMP messages of type “Fragmentation needed but Don’t Fragment (DF) set” between two hosts, potentially ca...

CVE-2001-0323

The ICMP path MTU PMTU discovery feature in various UNIX systems allows remote attackers to cause a denial of service by spoofing "ICMP Fragmentation needed but Don't Fragment DF set" packets between two target hosts, which could cause one host to lower its MTU when transmitting to the other host...

ICMP fragmentation required but DF set problems.

Hi all, The problem I'm exposing is quite obvious, but unfortunatelly can be used in a very simple way by script kiddies. SYNOPSIS It's possible to slowdown a lot connections between two arbirary hosts but at least one with the PMTU discovery enabled using some spoofed TCP/IP packet. Maybe you ca...

Re: ICMP fragmentation required but DF set problems.

This is a valid method, and known, to slow down a link between two hosts. In my paper "ICMP Usage In Scanning" currently version 2.5 Appendix B: ICMP "Fragmentation Needed but the Don't Fragment Bit was set" and the Path MTU Discovery Process Page 132, I have outlined what should be done accordin...