Shorewall vulnerability

Releases

• Ubuntu 5.04
• Ubuntu 4.10

Details

A firewall bypass vulnerability has been found in shorewall. If
MACLIST_TTL was set to a value greater than 0 or MACLIST_DISPOSITION
was set to “ACCEPT” in /etc/shorewall/shorewall.conf, and a client was
positively identified through its MAC address, that client bypassed
all other policies/rules in place. This could allow external computers
to get access to ports that are intended to be restricted by the
firewall policy.

Please note that this does not affect the default configuration, which
does not enable MAC based client identification.