Univention Corporate Server 4.3 erratum 190 (security)

This update addresses the following issues:
* Uncontrolled search path element in pg_dump and other client applications
  (CVE-2018-1058)
* Too-permissive access control list on function pg_logfile_rotate()
  (CVE-2018-1115)
* Certain host connection parameters defeat client-side security defenses
  (CVE-2018-10915)
* Missing authorization and memory disclosure in INSERT ... ON CONFLICT DO
  UPDATE statements (CVE-2018-10925)