Ubuntu 12.10 has reached it's end of life. Here the announcement:

Ubuntu announced its 12.10 (Quantal Quetzal) release more than 18 months
ago, on October 18, 2012. Since changes to the Ubuntu support cycle
mean that Ubuntu 13.04 has reached end of life before Ubuntu 12.10, the
support cycle for Ubuntu 12.10 has been extended slightly to overlap
with the release of Ubuntu 14.04 LTS. This will allow users to move
directly from Ubuntu 12.10 to Ubuntu 14.04 LTS (via Ubuntu 13.10).

This period of overlap is now coming to a close, and we will be retiring
Ubuntu 12.10 on Friday, May 16, 2014. At that time, Ubuntu Security
Notices will no longer include information or updated packages for
Ubuntu 12.10.

The supported upgrade path from Ubuntu 12.10 is via Ubuntu 13.10, though
we highly recommend that once you've upgraded to 13.10, you continue to
upgrade through to 14.04, as 13.10's support will end in July.

Instructions and caveats for the upgrade may be found at:

https://help.ubuntu.com/community/SaucyUpgrades
https://help.ubuntu.com/community/TrustyUpgrades

Ubuntu 13.10 and 14.04 continue to be actively supported with security
updates and select high-impact bug fixes. Announcements of security
updates for Ubuntu releases are sent to the ubuntu-security-announce
mailing list, information about which may be found at:

https://lists.ubuntu.com/mailman/listinfo/ubuntu-security-announce

Since its launch in October 2004 Ubuntu has become one of the most
highly regarded Linux distributions with millions of users in homes,
schools, businesses and governments around the world. Ubuntu is Open
Source software, costs nothing to download, and users are free to
customize or alter their software in order to meet their needs.

On behalf of the Ubuntu Release Team,

Adam Conrad