(RHSA-2016:1421) Important: 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.

Red Hat would like to thank Scott Geary (VendHQ) for reporting this issue.