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.
Exploitability
AV:NAC:MAu:NImpact
C:NI:PA:N4.3/AV:N/AC:M/Au:N/C:N/I:P/A:N