Apache HTTP Server Vulnerability - CVE-2016-5387
The Apache HTTP Server through 2.4.23 follows RFC 3875 section 4.1.18 and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable which might allow remote attackers to redirect an application39s outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request aka an quothttpoxyquot issue. NOTE: the vendor states quotThis mitigation has been assigned the identifier CVE-2016-5387quot in other words this is not a CVE ID for a vulnerability.