Ubuntu 4.10 : postfix vulnerability (USN-74-1)
High Nessus Plugin ID 20695
SynopsisThe remote Ubuntu host is missing one or more security-related patches.
DescriptionJean-Samuel Reynaud noticed a programming error in the IPv6 handling code of Postfix when /proc/net/if_inet6 is not available (which is the case in Ubuntu since Postfix runs in a chroot). If 'permit_mx_backup' was enabled in the 'smtpd_recipient_restrictions', Postfix turned into an open relay, i. e. erroneously permitted the delivery of arbitrary mail to any MX host which has an IPv6 address.
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected packages.