Fix (APAR):  PI42928

Status:  Fix

Release:  7.0.0.37

Operating System:  AIX,HP-UX,Linux,Solaris,Windows

Supersedes Fixes:  

CMVC Defect:  xxxxxx

Byte size of APAR:  3073858

Date: 2015-08-31

Abstract:  CVE-2015-3183 for IBM HTTP Server

Description/symptom of problem:  
PI42928 resolves the following problem:

ERROR DESCRIPTION:
An attacker sending a carefully crafted request to IBM HTTP 
Server could force intermediate caches to cache the wrong
responses.                                                    

LOCAL FIX:                                                      

PROBLEM SUMMARY:
IBM HTTP Server is vulnerable to HTTP request smuggling, 
caused by a chunk header parsing flaw.  A malicious attacker 
could cause intermediate caches to cache and send the wrong 
response for a given URL, bypass web application firewall 
protection, and possibly conduct XSS attacks.

PROBLEM CONCLUSION:
Mishandled chunked requests are now correctly handled. 
                                                               
This fix is targeted for IBM HTTP Server fix packs: 
- 7.0.0.39 
- 8.0.0.12 
- 8.5.5.7 


Directions to apply fix:  
Special Instructions: None

NOTE: The user must:
* For V6, have Administrative rights in Windows, or be the Actual Root User in
  UNIX environments.
* For V7, be logged in with the same authority level when unpacking a fix,
  fix pack, or refresh pack.
* For V6, be at V6.1.0.13 or newer of the Update Installer and for V7, be at
  V7.0.0.0 or newer of the Update Installer. Certain iFixes may require a
  newer version of the Update Installer and the Update Installer will inform you
 during the installation process if a newer version is required. This can be
  checked by reviewing the level of the Update Installer in file
  /updateinstaller/version.txt.

The Update Installer can be downloaded from the following link:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991

Note that there are two different methods for delivering iFixes, depending on the
contents.  The fix may be delivered either as a single file with a .pak extension
(such as 6.1.0.11-WS-WAS-IFPK12345.pak) or a single file with a .zip extension
(such as 6.1.0.11-WS-WAS-IFPK12345.zip) which then contains one or more files with
a .pak extension.

1) If your iFix is delivered as a single file with a .pak extension, Copy the .pak
   file directly to the maintenance directory. If your iFix is delivered as a
   single file with a .zip extension, unzip the file into the maintenance directory.

2) Stop IBM HTTP Server

3) Launch the Update Installer and click the Next button on the Welcome page.

4) Enter the directory path of the installation location of the WebSphere product
   you want to update, and click the Next button.

5) Select the "Install maintenance package" operation and click the Next button.

6) Enter the directory path of your maintenance directory where you have the
  maintenance packages (.pak files) and click the Next button.

7) The Available Maintenance Package to Install page should list all maintenance
   packages (.pak files) that it finds in the directory path provided in the
   previous step.  The Update Installer will select the correct maintenance
   packages based on your system configuration and will not allow an invalid
   combination to be installed.  Please keep the Update Installer recommendations
   and click the Next button and continue with the installation of the maintenance
   package.  To determine why some maintenance packages have been identified as
   not applicable, see description in log found in
   /logs/tmp*/updatelogs.txt

8) Please note that in the future, if a Feature Pack is installed or uninstalled,
   a different set of iFixes will be needed.  Use the Update Installer again at that
   time, with the maintenance directory location where these maintenance packages
   are stored, to determine the required interim fixes for the new WebSphere and
   Feature Pack(s) combination.

9) For V7, all platforms except Windows: In pre-install summary panel, use the
   "verify permission" feature to verify the user has permissions to apply updates
   to files associated with the selected maintenance.  Correct any file permissions
   before clicking next to start the install.

10) Restart IBM HTTP Server

Directions to remove fix:  
NOTE:
* The user must have Administrative rights in Windows, or be the Actual Root User
  in a UNIX environment.
* FIXES MUST BE REMOVED IN THE ORDER THEY WERE APPLIED
* DO NOT REMOVE A FIX UNLESS ALL FIXES APPLIED AFTER IT HAVE FIRST BEEN REMOVED
* YOU MAY REAPPLY ANY REMOVED FIX

Example: If your system has fix1, fix2, and fix3 applied in that order and fix2
is to be removed, fix3 must be removed first, fix2 removed, and fix3 re-applied.

1) Stop IBM HTTP Server
2) Start Update Installer
3) Enter the installation location of the WebSphere product you want to remove
   the fix.
4) Select  "Uninstall maintenance package" operation.
5) Enter the file name of the maintenance package to uninstall (PKxxxxx.pak).
6) UnInstall maintenance package.
7) Restart IBM HTTP Server


Directions to re-apply fix:  
1) Stop IBM HTTP Server.
2) Follow Directions to apply fix.
3) Restart IBM HTTP Server.


Additional Information: