_ _ _____ _ ___ _____ _ _ / / / / ____/ / / _/_ __/ / / / / /_/ / __/ / / / / / / / /_/ / / __ / /___/ /____/ / / / / __ / /_/ /_/_____/_____/___/ /_/ /_/ /_/ Helith - 0815 ------------------------------------------------------------------------ -------- Author : Rembrandt Date : 2009-04-09 Affected Software: OpenBSD Kernel Affected OS : OpenBSD 4.{3,4,5}, OpenBSD-current Propably older versions are affected as well Type : Denial of Service OSVDB : Milw0rm : 8406 CVE : ISS X-Force: : BID : 34482 Secunia : 34676 VUPEN ID : Trying to fix it responsible and get in contact with the vendor: -- OpenBSD -- Contacted 2009-04-09 15:35 GMT+1 Patch avaiable 2009-04-11 23:43 UTC We received no response nor a notification about an upcoming patch by the developers. -- END -- OpenBSDs PF firewall in OpenBSD 4.3 up to OpenBSD-current is prone to a remote Denial of Service during a null pointer dereference in relation with special crafted IP datagrams. If the firewall handles such a packet the kernel panics. Steps to reproduce: If you are behind a OpenBSD firewall this nmap scan should trigger the problem and crash your firewall device: nmap -sO $some_host_so_that_the_firewall_handles_the_packets For more informations please do read the patch issued by OpenBSD. Patches and Workaround: Patches are provided for OpenBSD 4.3, 4.4, 4.5 (upcoming, release 1st of may) and OpenBSD-current (via CVS only) and are avaiable at the errata website. The developers provide hints for a workaround at their errata website too. Kind regards, Rembrandt