Univention Corporate Server 4.2 erratum 349 (security)

This update addresses the following issue(s):
* A heap out-of-bounds write occurs in bitset_set_range() during regular
  expression compilation due to an uninitialized variable from an incorrect
  state transition. An incorrect state transition in parse_char_class() could
  create an execution path that leaves a critical local variable
  uninitialized until it's used as an index, resulting in an out-of-bounds
  write memory corruption. (CVE-2017-9228)
* A SIGSEGV occurs in left_adjust_char_head() during regular expression
  compilation. Invalid handling of reg->dmax in forward_search_range() could
  result in an invalid pointer dereference, normally as an immediate
  denial-of-service condition. (CVE-2017-9229)
* A heap out-of-bounds write or read occurs in next_state_val() during
  regular expression compilation. Octal numbers larger than 0xff are not
  handled correctly in fetch_token() and fetch_token_in_cc(). A malformed
  regular expression containing an octal number in the form of '\700' would
  produce an invalid code point value larger than 0xff in next_state_val(),
  resulting in an out-of-bounds write memory corruption. (CVE-2017-9226)
* A stack out-of-bounds read occurs in mbc_enc_len() during regular
  expression searching. Invalid handling of reg->dmin in
  forward_search_range() could result in an invalid pointer dereference, as
  an out-of-bounds read from a stack buffer. (CVE-2017-9227)
* A stack out-of-bounds read occurs in match_at() during regular expression
  searching. A logical error involving order of validation and access in
  match_at() could result in an out-of-bounds read from a stack buffer.
  (CVE-2017-9224)