"We recommend that you upgrade your apt packages." with apt of course... (via https://twitter.com/ioerror)
https://www.debian.org/security/2014/dsa-3025
"It was discovered that APT, the high level package manager, does not properly invalidate unauthenticated data (CVE-2014-0488), performs incorrect verification of 304 replies (CVE-2014-0487), does not perform the checksum check when the Acquire::GzipIndexes option is used (CVE-2014-0489) and does not properly perform validation for binary packages downloaded by the apt-get download command (CVE-2014-0490)."
(Score: 2) by _NSAKEY on Friday September 19 2014, @04:59PM
The steps for doing that can be found here [debian.org]