July 2005
Macromedia - JRun 4.0 Token Collision
ID: 00589
Ref: 548/05
Date: 15 July 2005:15:40:45
Version: 1
Title: Macromedia - JRun 4.0 Token Collision
Abstract: Under high load, JRun may generate two sessions with the same authentication token. This cannot be controlled by an attacker and it occurs very rarely, but it may cause two authenticated users to share information from a single user session.
Vendors affected: Macromedia
Applications affected: Macromedia
Title
=====
Macromedia - JRun 4.0 Token Collision
Detail
======
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MPSB05-05 - Security Patch available for JRun 4.0 token
collision.
Originally posted: July 14, 2005
http://www.macromedia.com/go/mpsb05-05
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Summary:
Under high load, JRun may generate two sessions with the
same authentication token. This cannot be controlled by
an attacker and it occurs very rarely, but it may cause
two authenticated users to share information from a single
user session.
~~~~~~~
Solution:
Macromedia has released a JRun 4.0 patch that can be
downloaded and applied. This only affects products based
on the JRun 4 server (listed below).
Download JRun 4.0 patch (ZIP, 9 KB):
http://www.macromedia.com/go/mpsb05-05
~~~~~~~
Affected Software Versions:
ColdFusion MX 7.0 Enterprise Multi-Server Edition
ColdFusion MX 6.1 Enterprise with JRun
JRun 4.0
~~~~~~~
Severity Rating:
Macromedia categorizes this issue as a moderate issue
and recommends users immediately evaluate their
configuration.
~~~~~~~
Details:
When a user is authenticated, JRun generates an internal
authentication token to track a user's information
(principal, credentials, etc.). Under load, it's possible
two users can obtain the same token number and shared
session information. Macromedia has received a report of
this occurring in a production system, but it happens very
infrequently, and there is no way for an attacker to cause
or control a collision.
The patch modifies the authentication token generation
algorithm to prevent generation of duplicate tokens.
~~~~~~~
Making the Changes:
NOTE: Back up your existing files before making changes.
As always, test the changes in a non-production environment
before applying the changes to production servers.
JRun 4.0 or ColdFusion MX 7.0 Multi-Server Edition:
1. Download the patch above and expand it.
2. Stop all JRun servers.
3. Place the jrun-hotfix-MPSB05-05.jar in the
{jrun_root}/servers/lib directory.
4. Restart JRun.
ColdFusion MX 7.0 Enterprise or ColdFusion MX 6.1 Enterprise
Edition (For ColdFusion 6.1, Updater 1 is required):
1. Download the patch above, and expand it.
2. Stop ColdFusion MX.
3. Place the jrun-hotfix-MPSB05-05.jar in the
{cf_root}/runtime/servers/lib directory.
4. (Create the {cf_root}/runtime/servers/lib directory if
it does not exist.)
On Unix Systems Only:
1. Edit the file {cf_root}/runtime/bin/jvm.config.
2. Find the JVM classpath section.
3. Add {application.home}/runtime/servers/lib as the first
entry in the java.class.path list.
Example: JVM classpath
java.class.path={application.home}/runtime/servers/lib,
{application.home}/runtime/../../src,{application.home}/lib/
cfusion.jar,{application.home}/runtime/lib/webservices.jar
4. Start ColdFusion MX
NOTE: This patch will be incorporated into ColdFusion MX 7.0
Updater 1 and JRun 4.0 Updater 6.
~~~~~~~
Acknowledgements:
Macromedia would like to thank Greg Ball from the University
of Virginia for reporting this vulnerability and for working
with us to help protect our customers' security.
~~~~~~~
Revisions:
July 14, 2005 - Bulletin first created.
~~~~~~~
Reporting Security Issues:
Macromedia is committed to addressing security issues
and providing customers with the information on how they
can protect themselves. If you identify what you believe
may be a security issue with a Macromedia product, please
send an e-mail to secure@macromedia.com. We will work to
appropriately address and communicate the issue.
~~~~~~~
Receiving Security Bulletins:
When Macromedia becomes aware of a security issue
that we believe significantly affects our products or
customers, we will notify customers when appropriate.
Typically this notification will be in the form of a
security bulletin explaining the issue and the response.
Macromedia customers who would like to receive
notification of new security bulletins when they are
released can sign up for our security notification
service.
For additional information on security issues at
Macromedia, please visit:
http://www.macromedia.com/security.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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OR FIXES PROVIDED BY MACROMEDIA IN THIS BULLETIN ARE
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