Univention Corporate Server 4.3 erratum 177 (security)

This update addresses the following issues:
* avfilter/vf_transpose: Fix used plane count (CVE-2018-6392)
* avcodec/utvideodec: Fix bytes left check in decode_frame() (CVE-2018-6621)
* avcodec/utvideodec: Check subsample factors (CVE-2018-7557)
* avcodec/utvideodec: Set pro flag based on fourcc (CVE-2018-10001)
* avcodec/mpeg4videoenc: Use 64 bit for times in mpeg4_encode_gop_header()
  (CVE-2018-12458)
* avformat/movenc: Do not pass AVCodecParameters in avpriv_request_sample
  (CVE-2018-13300)
* avformat/movenc: Check that frame_types other than
  EAC3_FRAME_TYPE_INDEPENDENT have a supported substream id (CVE-2018-13302)
* libavformat/movenc.c in FFmpeg allows attackers to cause a denial of
  service (application crash caused by a divide-by-zero error) with a user
  crafted Waveform audio file. (CVE-2018-14394)
* avformat/movenc: Write version 2 of audio atom if channels is not known
  (CVE-2018-14395)
* FFmpeg contains multiple out of array access vulnerabilities in the mms
  protocol that can result in attackers accessing out of bound data. This
  attack appear to be exploitable via network connectivity.
  (CVE-2018-1999010)
* FFmpeg contains a CWE-835: Infinite loop vulnerability in pva format
  demuxer that can result in a Vulnerability that allows attackers to consume
  excessive amount of resources like CPU and RAM. This attack appear to be
  exploitable via specially crafted PVA file has to be provided as input.
  (CVE-2018-1999012)
* FFmpeg contains a use-after-free vulnerability in the realmedia demuxer
  that can result in vulnerability allows attacker to read heap memory. This
  attack appear to be exploitable via specially crafted RM file has to be
  provided as input. (CVE-2018-1999013)