CVE-2014-3581

The cache_merge_headers_out function in modules/cache/cache_util.c in the mod_cache module in the Apache HTTP Server before 2.4.11 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an empty HTTP Content-Type header.

The cache_merge_headers_out function in modules/cache/cache_util.c in the mod_cache module in the Apache HTTP Server before 2.4.11 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an empty HTTP Content-Type header.

Updated apache packages fix security vulnerabilities:

A NULL pointer dereference flaw was found in the way the mod_cache httpd module handled Content-Type headers. A malicious HTTP server could cause the httpd child process to crash when the Apache HTTP server was configured to proxy to a server with caching enabled (CVE-2014-3581).

A flaw was found in the way httpd handled HTTP Trailer headers when processing requests using chunked encoding. A malicious client could use Trailer headers to set additional HTTP headers after header processing was performed by other modules. This could, for example, lead to a bypass of header restrictions defined with mod_headers (CVE-2013-5704).

Note: With this update, httpd has been modified to not merge HTTP Trailer headers with other HTTP request headers. A newly introduced configuration directive MergeTrailers can be used to re-enable the old method of processing Trailer headers, which also re-introduces the aforementioned flaw.

This update also fixes the following bug:

Prior to this update, the mod_proxy_wstunnel module failed to set up an SSL connection when configured to use a back end server using the "wss:" URL scheme, causing proxied connections to fail. In these updated packages, SSL is used when proxying to "wss:" back end servers (rhbz#1141950).

These are all security issues fixed in the apache2-2.4.23-4.1 package on the GA media of openSUSE Tumbleweed.

This update for the Apache Web Server introduces directives to control two protocol options:

* HttpContentLengthHeadZero: Allow responses to HEAD request with
  Content-Length of 0
* HttpExpectStrict: Allow the administrator to control whether clients
  must send '100-continue'

MODULE_MAGIC_NUMBER_MINOR has been increased to 24, as this change is not forward-compatible. Modules built against this release might not work correctly with older releases of the Apache Web Server.

Apache2 updated to fix four security issues and one non-security bug.

The following vulnerabilities have been fixed:

• mod_headers rules could be bypassed via chunked requests. Adds 'MergeTrailers' directive to restore legacy behavior. (bsc#871310, CVE-2013-5704)
• An empty value in Content-Type could lead to a crash through a null pointer dereference and a denial of service. (bsc#899836, CVE-2014-3581)
• Remote attackers could bypass intended access restrictions in mod_lua LuaAuthzProvider when multiple Require directives with different arguments are used. (bsc#909715, CVE-2014-8109)
• Remote attackers could cause a denial of service (child-process crash) by sending a crafted WebSocket Ping frame after a Lua script has called the wsupgrade function. (bsc#918352, CVE-2015-0228)

The following non-security issues have been fixed:

• The Apache2 systemd service file was changed to fix situation where apache wouldn't start at boot when using an encrypted certificate because the user wasn't prompted for password during boot. (bsc#792309)

Additionally, mod_imagemap is now included by default in the package. (bsc#923090)

The cache_merge_headers_out function in modules/cache/cache_util.c in the mod_cache module in the Apache HTTP Server before 2.4.11 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an empty HTTP Content-Type header.

Martin Holst Swende discovered that the mod_headers module allowed HTTP trailers to replace HTTP headers during request processing. A remote attacker could possibly use this issue to bypass RequestHeaders directives. (CVE-2013-5704)

Mark Montague discovered that the mod_cache module incorrectly handled empty HTTP Content-Type headers. A remote attacker could use this issue to cause the server to stop responding, leading to a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 14.10. (CVE-2014-3581)

Teguh P. Alko discovered that the mod_proxy_fcgi module incorrectly handled long response headers. A remote attacker could use this issue to cause the server to stop responding, leading to a denial of service. This issue only affected Ubuntu 14.10. (CVE-2014-3583)

It was discovered that the mod_lua module incorrectly handled different arguments within different contexts. A remote attacker could possibly use this issue to bypass intended access restrictions. This issue only affected Ubuntu 14.10. (CVE-2014-8109)

Guido Vranken discovered that the mod_lua module incorrectly handled a specially crafted websocket PING in certain circumstances. A remote attacker could possibly use this issue to cause the server to stop responding, leading to a denial of service. This issue only affected Ubuntu 14.10. (CVE-2015-0228)