USN-2183-1 fixed a vulnerability in dpkg. Javier Serrano Polo discovered that the fix introduced a vulnerability in releases with an older version of the patch utility. This update fixes the problem.
Original advisory details:
Jakub Wilk discovered that dpkg incorrectly certain paths and symlinks when unpacking source packages. If a user or an automated system were tricked into unpacking a specially crafted source package, a remote attacker could modify files outside the target unpack directory, leading to a denial of service or potentially gaining access to the system.