-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2015.1520
        Security Bulletin: Vulnerability in Diffie-Hellman ciphers
              affects IBM Datapower Gateways (CVE-2015-4000)
                               11 June 2015

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           IBM DataPower Gateways
Publisher:         IBM
Operating System:  Network Appliance
Impact/Access:     Access Privileged Data         -- Remote/Unauthenticated
                   Provide Misleading Information -- Remote/Unauthenticated
Resolution:        Mitigation
CVE Names:         CVE-2015-4000  

Reference:         ESB-2015.1470
                   ESB-2015.1469
                   ESB-2015.1466
                   ESB-2015.1463
                   ESB-2015.1455
                   ESB-2015.1454
                   ESB-2015.1453
                   ESB-2015.1452
                   ESB-2015.1445
                   ESB-2015.1443
                   ESB-2015.1432
                   ESB-2015.1425

Original Bulletin: 
   http://www-01.ibm.com/support/docview.wss?uid=swg21959060

- --------------------------BEGIN INCLUDED TEXT--------------------

Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects IBM 
Datapower Gateways (CVE-2015-4000)

Security Bulletin

Document information

More support for:

IBM DataPower Gateways

Software version:

6.0.0, 6.0.1, 7.0.0, 7.1

Operating system(s):

Firmware

Reference #:

1959060

Modified date:

2015-06-08

Summary

The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key 
exchange protocol affects IBM Datapower Gateways.

Vulnerability Details

CVEID: CVE-2015-4000

DESCRIPTION: The TLS protocol could allow a remote attacker to obtain 
sensitive information, caused by the failure to properly convey a DHE_EXPORT 
ciphersuite choice. An attacker could exploit this vulnerability using 
man-in-the-middle techniques to force a downgrade to 512-bit export-grade 
cipher. Successful exploitation could allow an attacker to recover the session
key as well as modify the contents of the traffic. This vulnerability is 
commonly referred to as "Logjam".

    CVSS Base Score: 4.3

    CVSS Temporal Score: See 
    https://exchange.xforce.ibmcloud.com/vulnerabilities/103294 for the current 
    score

    CVSS Environmental Score*: Undefined

    CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:N/A:N)

Affected Products and Versions

All DataPower products and versions that are configured to perform SSL/TLS 
transactions as a client.

Remediation/Fixes

None

Workarounds and Mitigations

DataPower appliances acting as an SSL server are not vulnerable.

For appliances acting as an SSL client, disable DH ciphers in DataPower.

To disable the DH ciphers in DataPower, refer to the steps below.

    1. Quiesce all domains and services to stop traffic to the appliance. System
    quiesce and unquiesce commands can be run by navigating to Administration > 
    Main > System Control.

    2. Select Objects > Crypto Configuration > Crypto Profile in the left 
    navigation pane. For all the crypto profiles that are configured in the 
    Configure Crypto Profile page, suffix the existing Ciphers string with a value
    :!DH:!kEDH and click Apply.

For example, if you have a default configuration, the updates appears as 
below:

Default cipher string: HIGH:MEDIUM:!aNULL:!eNULL:@STRENGTH

DH disabled cipher string: HIGH:MEDIUM:!aNULL:!eNULL:@STRENGTH:!DH:!kEDH

Note that DH must be disabled in all the crypto profiles configured in all the
domains when used in an SSL client profile.

You should verify applying this configuration change does not cause any 
compatibility issues.

Not disabling the DH stream cipher will expose yourself to the attack 
described above. IBM recommends that you review your entire environment to 
identify other areas where you have enabled the DH stream cipher and take 
appropriate mitigation and remediation actions.

Get Notified about Future Security Bulletins

Subscribe to My Notifications to be notified of important product support 
alerts like this.

References

Complete CVSS Guide

On-line Calculator V2

Related information

IBM Secure Engineering Web Portal

IBM Product Security Incident Response Blog

Acknowledgement

Reported to IBM by The WeakDH team at https://weakdh.org

*The CVSS Environment Score is customer environment specific and will 
ultimately impact the Overall CVSS Score. Customers can evaluate the impact of
this vulnerability in their environments by accessing the links in the 
Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the 
Common Vulnerability Scoring System (CVSS) is an "industry open standard 
designed to convey vulnerability severity and help to determine urgency and 
priority of response." IBM PROVIDES THE CVSS SCORES "AS IS" WITHOUT WARRANTY 
OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT 
OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=leJ3
-----END PGP SIGNATURE-----