Description
Apache Tomcat 7.x through 7.0.70 and 8.x through 8.5.4, when the CGI Servlet is enabled, 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 "A mitigation is planned for future releases of Tomcat, tracked as CVE-2016-5388"; in other words, this is not a CVE ID for a vulnerability.
Remediation
References
http://lists.opensuse.org/opensuse-updates/2016-09/msg00025.html
http://rhn.redhat.com/errata/RHSA-2016-1624.html
http://rhn.redhat.com/errata/RHSA-2016-2045.html
http://rhn.redhat.com/errata/RHSA-2016-2046.html
http://www.kb.cert.org/vuls/id/797896
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.html
http://www.securityfocus.com/bid/91818
http://www.securitytracker.com/id/1036331
https://access.redhat.com/errata/RHSA-2016:1635
https://access.redhat.com/errata/RHSA-2016:1636
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03770en_us
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05324759
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722
https://httpoxy.org/
https://lists.apache.org/thread.html/053d9ce4d579b02203db18545fee5e33f35f2932885459b74d1e4272%40%3Cissues.activemq.apache.org%3E
https://lists.apache.org/thread.html/6b414817c2b0bf351138911c8c922ec5dd577ebc0b9a7f42d705752d%40%3Cissues.activemq.apache.org%3E
https://lists.apache.org/thread.html/6d3d34adcf3dfc48e36342aa1f18ce3c20bb8e4c458a97508d5bfed1%40%3Cissues.activemq.apache.org%3E
https://lists.apache.org/thread.html/r2853582063cfd9e7fbae1e029ae004e6a83482ae9b70a698996353dd%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rc6b2147532416cc736e68a32678d3947b7053c3085cf43a9874fd102%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rf21b368769ae70de4dee840a3228721ae442f1d51ad8742003aefe39%40%3Cusers.tomcat.apache.org%3E
https://lists.debian.org/debian-lts-announce/2019/08/msg00015.html
https://tomcat.apache.org/tomcat-7.0-doc/changelog.html
https://www.apache.org/security/asf-httpoxy-response.txt
Related Vulnerabilities
CVE-2018-5382 Vulnerability in maven package org.bouncycastle:bcprov-jdk16
CVE-2017-1000404 Vulnerability in maven package se.diabol.jenkins.pipeline:delivery-pipeline-plugin
CVE-2019-13173 Vulnerability in maven package org.webjars.npm:fstream
CVE-2021-31411 Vulnerability in maven package com.vaadin:flow-server
CVE-2021-27807 Vulnerability in maven package org.apache.pdfbox:pdfbox