Univention Corporate Server 4.2 erratum 324 (security)

This update addresses the following issues:
* Activate mod_reqtimeout in new installs and during updates from before
  2.4.10-10+deb8u8. It was wrongly not activated in new installs since
  jessie. This made the default installation vulnerable to some DoS attacks.
* mod_session_crypto was encrypting its data/cookie using the configured
  ciphers with possibly either CBC or ECB modes of operation (AES256-CBC by
  default), hence no selectable or builtin authenticated encryption. This
  made it vulnerable to padding oracle attacks, particularly with CBC.
  (CVE-2016-0736)
* Malicious input to mod_auth_digest can cause the server to crash, and each
  instance continues to crash even for subsequently valid requests.
  (CVE-2016-2161)
* Apache was liberal in the whitespace accepted from requests and sent in
  response lines and headers. Accepting these different behaviors represented
  a security concern when httpd participates in any chain of proxies or
  interacts with back-end application servers, either through mod_proxy or
  using conventional CGI mechanisms, and may result in request smuggling,
  response splitting and cache pollution. (CVE-2016-8743)
* In Apache use of the ap_get_basic_auth_pw() by third-party modules outside
  of the authentication phase may lead to authentication requirements being
  bypassed. (CVE-2017-3167)
* mod_ssl may dereference a NULL pointer when third-party modules call
  ap_hook_process_connection() during an HTTP request to an HTTPS port.
  (CVE-2017-3169)
* The HTTP strict parsing changes introduced a bug in token list parsing,
  which allows ap_find_token() to search past the end of its input string. By
  maliciously crafting a sequence of request headers, an attacker may be able
  to cause a segmentation fault, or to force ap_find_token() to return an
  incorrect value. (CVE-2017-7668)
* mod_mime can read one byte past the end of a buffer when sending a
  malicious Content-Type response header. (CVE-2017-7679)
* The value placeholder in [Proxy-]Authorization headers of type 'Digest' was
  not initialized or reset before or between successive key=value assignments
  by mod_auth_digest. Providing an initial key with no '=' assignment could
  reflect the stale value of uninitialized pool memory used by the prior
  request, leading to leakage of potentially confidential information, and a
  segfault in other cases resulting in denial of service. (CVE-2017-9788)
* Apache httpd allows remote attackers to read secret data from process
  memory if the Limit directive can be set in a user's .htaccess file, or if
  httpd.conf has certain misconfigurations, aka Optionsbleed. (CVE-2017-9798)
* mod_authnz_ldap, if configured with AuthLDAPCharsetConfig, uses the
  Accept-Language header value to lookup the right charset encoding when
  verifying the user's credentials. If the header value is not present in the
  charset conversion table, a fallback mechanism is used to truncate it to a
  two characters value to allow a quick retry (for example, 'en-US' is
  truncated to 'en'). A header value of less than two characters forces an
  out of bound write of one NUL byte to a memory location that is not part of
  the string. In the worst case, quite unlikely, the process would crash
  which could be used as a Denial of Service attack. In the more likely case,
  this memory is already reserved for future use and the issue has no effect
  at all. (CVE-2017-15710)
* The expression specified in <FilesMatch> could match '$' to a newline
  character in a malicious filename, rather than matching only the end of the
  filename. This could be exploited in environments where uploads of some
  files are are externally blocked, but only by matching the trailing portion
  of the filename. (CVE-2017-15715)
* When mod_session is configured to forward its session data to CGI
  applications (SessionEnv on, not the default), a remote user may influence
  their content by using a "Session" header. This comes from the
  "HTTP_SESSION" variable name used by mod_session to forward its data to
  CGIs, since the prefix "HTTP_" is also used by the Apache HTTP Server to
  pass HTTP header fields, per CGI specifications. (CVE-2018-1283)
* A specially crafted request could have crashed the Apache HTTP Server due
  to an out of bound access after a size limit is reached by reading the HTTP
  header. This vulnerability is considered very hard if not impossible to
  trigger in non-debug mode (both log and build level), so it is classified
  as low risk for common server usage. (CVE-2018-1301)
* A specially crafted HTTP request header could have crashed the Apache HTTP
  Server due to an out of bound read while preparing data to be cached in
  shared memory. It could be used as a Denial of Service attack against users
  of mod_cache_socache. The vulnerability is considered as low risk since
  mod_cache_socache is not widely used, mod_cache_disk is not concerned by
  this vulnerability. (CVE-2018-1303)
* When generating an HTTP Digest authentication challenge, the nonce sent to
  prevent reply attacks was not correctly generated using a pseudo-random
  seed. In a cluster of servers using a common Digest authentication
  configuration, HTTP requests could be replayed across servers by an
  attacker without detection. (CVE-2018-1312)