OpenBSD Bridged Network ICMP Denial Of Service Vulnerability

Bugtraq ID:	11044
Class:	Design Error
CVE:
Remote:	Yes
Local:	No
Published:	Aug 25 2004 12:00AM
Updated:	Aug 25 2004 12:00AM
Credit:	"Vafa Izadinia" <[email protected]> disclosed this issue to the vendor.
Vulnerable:	OpenBSD OpenBSD 3.5 OpenBSD OpenBSD 3.4 OpenBSD OpenBSD 3.3 OpenBSD OpenBSD 3.2
Not Vulnerable:	OpenBSD OpenBSD -current

OpenBSD Bridged Network ICMP Denial Of Service Vulnerability

The implementation of bridging in OpenBSD is reportedly susceptible to a denial of service vulnerability.

This vulnerability presents itself when an OpenBSD host is configured to bridge two or more networks. Additionally, the 'link2' flag must be set on the bridging device. This flag is designed to transparently join multiple networks via an IPSec VPN tunnel.

This vulnerability may allow an attacker to crash or reboot affected computers, denying service to legitimate users.

A fix was applied in CVS to OpenBSD-current on 18 Aug 2004.

OpenBSD Bridged Network ICMP Denial Of Service Vulnerability

An exploit is not required.

OpenBSD Bridged Network ICMP Denial Of Service Vulnerability

Solution:
OpenBSD has fixed this vulnerability in OpenBSD-current as of 18 Aug 2004.

OpenBSD Bridged Network ICMP Denial Of Service Vulnerability

References:

• OpenBSD Homepage (OpenBSD)
  
• Vulnerability: OpenBSD 3.5 Kernel Panic. ("Vafa Izadinia" )