Description
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.
Remediation
References
Related Vulnerabilities
Drupal Permissions, Privileges, and Access Controls Vulnerability (CVE-2016-7570)
Dolibarr Unrestricted Upload of File with Dangerous Type Vulnerability (CVE-2017-9840)
Oracle JRE CVE-2013-2472 Vulnerability (CVE-2013-2472)
Envoy Proxy Uncontrolled Resource Consumption Vulnerability (CVE-2020-12603)