Univention Corporate Server 4.2 erratum 66 (security)

This update addresses the following issues:
* The ASTERIX dissector could go into an infinite loop (CVE-2017-5596)
* The DHCPv6 dissector could go into a large loop (CVE-2017-5597)
* The NetScaler file parser could enter an infinite loop (CVE-2017-6467)
* The NetScaler file parser could crash (CVE-2017-6468)
* The LDSS dissector could crash (CVE-2017-6469)
* The IAX2 dissector could enter an infinite loop (CVE-2017-6470)
* The WSP dissector could enter an infinite loop (CVE-2017-6471)
* The K12 file parser could crash (CVE-2017-6473)
* The NetScaler file parser could enter an infinite loop (CVE-2017-6474)
* The RTMPT dissector could enter an infinite loop (CVE-2017-6472)
* Fix memory exhaustion/infinite loop via malformed STANAG 4607 capture file
  (CVE-2017-6014)