Errata overview
Errata ID 41
Date 2018-05-16
Source package apache2
Fixed in version 2.4.25-3+deb9u4A~
This update addresses the following issues:
* 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)
Additional notes
CVE ID CVE-2017-15710
UCS Bug number #46772