The remote host is missing an update to apt announced via advisory USN-762-1.

The problem can be corrected by upgrading your system to the following package versions: Ubuntu 6.06 LTS: apt 0.6.43.3ubuntu3.1 Ubuntu 8.04 LTS: apt 0.7.9ubuntu17.2 Ubuntu 8.10: apt 0.7.14ubuntu6.1 In general, a standard system upgrade is sufficient to effect the necessary changes. https://secure1.securityspace.com/smysecure/catid.html?in=USN-762-1

Alexandre Martani discovered that the APT daily cron script did not check the return code of the date command. If a machine is configured for automatic updates and is in a time zone where DST occurs at midnight, under certain circumstances automatic updates might not be applied and could become permanently disabled. (CVE-2009-1300) Michael Casadevall discovered that APT did not properly verify repositories signed with a revoked or expired key. If a repository were signed with only an expired or revoked key and the signature was otherwise valid, APT would consider the repository valid. (https://launchpad.net/bugs/356012)