CVE-2011-3374

It was found that apt-key in apt, all versions, do not correctly validate gpg keys with the master keyring, leading to a potential man-in-the-middle attack.

CVE-2011-1829

APT before 0.8.15.2 does not properly validate inline GPG signatures, which allows man-in-the-middle attackers to install modified packages via vectors involving lack of an initial clearsigned message.

CVE-2013-1051

apt 0.8.16, 0.9.7, and possibly other versions does not properly handle InRelease files, which allows man-in-the-middle attackers to modify packages before installation via unknown vectors, possibly related to integrity checking and the use of third-party repositories.

CVE-2014-0478

APT before 1.0.4 does not properly validate source packages, which allows man-in-the-middle attackers to download and install Trojan horse packages by removing the Release signature.