Univention Corporate Server 4.2 erratum 77 (security)

This update addresses the following issue(s):
* dmcrypt-get-device, as shipped in the eject package of Debian and Ubuntu,
  does not check the return value of the (1) setuid or (2) setgid function,
  which might cause dmcrypt-get-device to execute code, which was intended to
  run as an unprivileged user, as root. (CVE-2017-6964)