Univention Corporate Server 4.2 erratum 479 (security)

This update addresses the following issues:
* SMTP command injection via CRLF sequences in RCPT TO or MAIL FROM commands
  in Net::SMTP (CVE-2015-9096)
* Fiddle::Function.new heap buffer overflow (CVE-2016-2339)
* IV Reuse in GCM Mode (CVE-2016-7798)
* Buffer underrun vulnerability in Kernel.sprintf (CVE-2017-0898)
* Escape sequence in the "summary" field of gemspec (CVE-2017-0899)
* No size limit in summary length of gem spec (CVE-2017-0900)
* Arbitrary file overwrite due to incorrect validation of specification name
  (CVE-2017-0901)
* DNS hijacking vulnerability (CVE-2017-0902)
* Unsafe object deserialization through YAML formatted gem specifications
  (CVE-2017-0903)
* Escape sequence injection vulnerability in the Basic authentication of
  WEBrick (CVE-2017-10784)
* Buffer underrun in OpenSSL ASN1 decode (CVE-2017-14033)
* Arbitrary heap exposure during a JSON.generate call (CVE-2017-14064)
* Command injection vulnerability in Net::FTP (CVE-2017-17405)
* HTTP response splitting in WEBrick (CVE-2017-17742)
* Command injection in lib/resolv.rb:lazy_initialize() allows arbitrary code
  execution (CVE-2017-17790)
* Unintentional file and directory creation with directory traversal in
  tempfile and tmpdir (CVE-2018-6914)
* DoS by large request in WEBrick (CVE-2018-8777)
* Buffer under-read in String#unpack (CVE-2018-8778)
* Unintentional socket creation by poisoned NULL byte in UNIXServer and
  UNIXSocket (CVE-2018-8779)
* Unintentional directory traversal by poisoned NULL byte in Dir
  (CVE-2018-8780)
* Infinite loop vulnerability due to negative size in tar header causes
  Denial of Service (CVE-2018-1000075)
* Improper verification of signatures in tarball allows to install mis-signed
  gem (CVE-2018-1000076)
* Missing URL validation on spec home attribute allows malicious gem to set
  an invalid homepage URL (CVE-2018-1000077)
* XSS vulnerability in homepage attribute when displayed via gem server
  (CVE-2018-1000078)
* Path traversal issue during gem installation allows to write to arbitrary
  filesystem locations (CVE-2018-1000079)