Univention Corporate Server 4.3 erratum 362 (security)

This update addresses the following issues:
* Improperly implemented security check in zsetdevice function in
  psi/zdevice.c (CVE-2018-19409)
* psi/zdevice2.c allows remote attackers to bypass intended access
  restrictions because available stack space is not checked when the device
  remains the same. (CVE-2018-19475)
* psi/zicc.c allows remote attackers to bypass intended access restrictions
  because of a setcolorspace type confusion. (CVE-2018-19476)
* psi/zfjbig2.c allows remote attackers to bypass intended access
  restrictions because of a JBIG2Decode type confusion. (CVE-2018-19477)