(Red Hat Issues Fix for JBoss) Apache HTTPD CGI Application "Proxy:" Header Processing Flaw Lets Remote Users Redirect the Target CGI Application Requests to an Arbitrary Web Proxy in Certain Cases
SecurityTracker Alert ID: 1036656|
SecurityTracker URL: http://securitytracker.com/id/1036656
(Links to External Site)
Date: Aug 18 2016
Disclosure of system information, Disclosure of user information, Host/resource access via network, Modification of system information, Modification of user information|
Fix Available: Yes Vendor Confirmed: Yes Exploit Included: Yes |
A vulnerability reported in CGI applications that run on Apache HTTPD. A remote user can redirect the target CGI application requests to an arbitrary web proxy in certain cases. JBoss is affected.|
On systems where the Apache HTTPD server is configured to proxy HTTP requests and the target CGI application relies on the HTTP_PROXY environment variable in a trusted manner, a remote user can send (or can conduct a man-in-the-middle attack to insert or modify) a specially crafted HTTP "Proxy:" header to cause the target CGI application to proxy HTTP connections to an arbitrary port on an arbitrary server. This can be exploited to set the HTTP_PROXY variable on the target CGI application server and cause CGI application server internal requests to be proxied, in certain cases.
The vulnerability resides in the CGI applications that use the HTTP_PROXY variable.
[Editor's note: This is not an Apache HTTPD vulnerability, per se. Rather, it is a vulnerability in CGI modules or applications that may run on Apache HTTPD or other web server platforms.]
Other CGI application platforms are affected.
The original advisory is available at:
Dominic Scheirlinck and Scott Geary of Vend reported this vulnerability. Other researchers have reported aspects of this vulnerability affecting various applications since at least 2001.
A remote user that can conduct a man-in-the-middle attack can redirect the target CGI application requests to an arbitrary web proxy in certain cases.|
Red Hat has issued a fix for JBoss.|
The Red Hat advisory is available at:
Vendor URL: rhn.redhat.com/errata/RHSA-2016-1625.html (Links to External Site)
Access control error|
|Underlying OS: Linux (Red Hat Enterprise)|
This archive entry is a follow-up to the message listed below.|
Source Message Contents
Subject: [RHSA-2016:1625-02] Important: Red Hat JBoss Core Services Apache HTTP 2.4.6 Service Pack 1 security update|
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Red Hat Security Advisory
Synopsis: Important: Red Hat JBoss Core Services Apache HTTP 2.4.6 Service Pack 1 security update
Advisory ID: RHSA-2016:1625-02
Product: Red Hat JBoss Core Services
Advisory URL: https://rhn.redhat.com/errata/RHSA-2016-1625.html
Issue date: 2016-08-17
CVE Names: CVE-2016-5387
Red Hat JBoss Core Services Service Pack 1 is now available from the Red
Hat Customer Portal for Solaris and Microsoft Windows systems.
Red Hat Product Security has rated this update as having a security impact
of Important. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available for each vulnerability
from the CVE link(s) in the References section.
This release of Red Hat JBoss Core Services Service Pack 1 serves as a
replacement for JBoss Core Services Apache HTTP Server.
* It was discovered that Apache HTTP Server 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
Note: After this update, Apache HTTP Server will no longer pass the value
of the Proxy request header to scripts via the HTTP_PROXY environment
Red Hat would like to thank Scott Geary (VendHQ) for reporting this issue.
The References section of this erratum contains a download link (you must
log in to download the update). Before applying the update, back up your
existing Red Hat JBoss Web Server installation (including all applications
and configuration files).
After installing the updated packages, the httpd daemon will be restarted
4. Bugs fixed (https://bugzilla.redhat.com/):
1353755 - CVE-2016-5387 Apache HTTPD: sets environmental variable based on user supplied Proxy request header
The Red Hat security contact is <email@example.com>. More contact
details at https://access.redhat.com/security/team/contact/
Copyright 2016 Red Hat, Inc.
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