(RHSA-2016:1420) Important: httpd24-httpd security update

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• It was discovered that httpd used the value of the Proxy header from HTTP requests to initialize the HTTP_PROXY environment variable for CGI scripts, which in turn was incorrectly used by certain HTTP client implementations to configure the proxy for outgoing HTTP requests. A remote attacker could possibly use this flaw to redirect HTTP requests performed by a CGI script to an attacker-controlled proxy via a malicious HTTP request. (CVE-2016-5387)

Note: After this update, httpd will no longer pass the value of the Proxy request header to scripts via the HTTP_PROXY environment variable.

• A flaw was found in the way httpd performed client authentication using X.509 client certificates. When the HTTP/2 protocol was enabled, a remote attacker could use this flaw to access resources protected by certificate authentication without providing a valid client certificate. (CVE-2016-4979)

Red Hat would like to thank Scott Geary (VendHQ) for reporting CVE-2016-5387 and Apache Software Foundation for reporting CVE-2016-4979. Upstream acknowledges Erki Aring (Liewenthal Electronics Ltd) as the original reporter of CVE-2016-4979.