The remote host is missing an update to shorewall announced via advisory DSA 849-1. Supernaut noticed that shorewall, the Shoreline Firewall, could generate an iptables configuration which is significantly more permissive than the rule set given in the shorewall configuration, if MAC verification are used in a non-default manner. When MACLIST_DISPOSITION is set to ACCEPT in the shorewall.conf file, all packets from hosts which fail the MAC verification pass through the firewall, without further checks. When MACLIST_TTL is set to a non-zero value, packets from hosts which pass the MAC verification pass through the firewall, again without further checks. The old stable distribution (woody) is not affected by this problem.

For the stable distribution (sarge) this problem has been fixed in version 2.2.3-2. For the unstable distribution (sid) this problem has been fixed in version 2.4.1-2. We recommend that you upgrade your shorewall package. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20849-1