Univention Corporate Server 4.2 erratum 356 (security)

This update addresses the following issue:
* libwpd mishandles iterators, which allows remote attackers to cause a
  denial of service (heap-based buffer over-read in the WPXTableList class in
  WPXTable.cpp). This vulnerability can be triggered in LibreOffice before
  5.3.7. It may lead to suffering a remote attack against a LibreOffice
  application. (CVE-2017-14226)