The pkgAcqMetaClearSig::Failed method in apt-pkg/acquire-item.cc in Advanced Package Tool (APT) 0.8.11 through 0.8.15.10 and 0.8.16 before 0.8.16~exp13, when updating from repositories that use InRelease files, allows man-in-the-middle attackers to install arbitrary packages by preventing a user from downloading the new InRelease file, which leaves the original InRelease file active and makes it more difficult to detect that the Packages file is modified and unsigned.

APT 0.7.x before 0.7.25 and 0.8.x before 0.8.16, when using the apt-key net-update to import keyrings, relies on GnuPG argument order and does not check GPG subkeys, which might allow remote attackers to install altered packages via a man-in-the-middle (MITM) attack. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-3587.

APT 0.7.x before 0.7.25 and 0.8.x before 0.8.16, when using the apt-key net-update to import keyrings, relies on GnuPG argument order and does not check GPG subkeys, which might allow remote attackers to install Trojan horse packages via a man-in-the-middle (MITM) attack.