Univention Corporate Server 4.2 erratum 330 (security)

This update addresses the following issues:
* CVE-2018-5125: Memory safety bugs fixed in Firefox 59 and Firefox ESR 52.7
* CVE-2018-5127: Buffer overflow manipulating SVG animatedPathSegList
* CVE-2018-5129: Out-of-bounds write with malformed IPC messages
* CVE-2018-5130: Mismatched RTP payload type can trigger memory corruption
* CVE-2018-5131: Fetch API improperly returns cached copies of
  no-store/no-cache resources
* CVE-2018-5144: Integer overflow during Unicode conversion
* CVE-2018-5145: Memory safety bugs fixed in Firefox ESR 52.7
* CVE-2018-5146: Vorbis audio processing out of bounds write
* CVE-2018-5147: Out of bounds memory write in libtremor
* CVE-2018-5148: Use-after-free in compositor potentially allows code
  execution