View at Official ubuntu advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2016-5387 medium priority: Ubuntu including 1 source packages (apache2), 5 status rows across 5 suites (precise, trusty, upstream, wily, xenial): released 4, needs-triage 1.
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 application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue. NOTE: the vendor states "This mitigation has been assigned the identifier CVE-2016-5387"; in other words, this is not a CVE ID for a vulnerability.