Security Bulletin: Vulnerability with Diffie-Hellman ciphers may affect IBM i2 Intelligence Analysis Platform (CVE-2015-4000)

Summary

The LogJam Attack on Diffie-Hellman ciphers (CVE-2015-4000) may affect some configurations of the IBM WebSphere Application Server used with the IBM i2 Intelligence Analysis Platform. The IBM HTTP Server used by IBM i2 Intelligence Analysis Platform is not affected.

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&gt; 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

The following IBM Intelligence Analysis Platform version may be affected: Version 3.0.9

• IBM Counter Fraud Management 1.5.0.5 supports IAP Version 3.0.9.
• IBM Counter Fraud Management 2.0.0.0 supports IAP Version 3.0.9.

Remediation/Fixes

You should apply the correct Interim Fix as noted below for the IBM SDK Java Technology Edition. You will also need to update your java.security file to add:

jdk.tls.disabledAlgorithms=SSLv3, RC4, DH keySize <768

Adding this line to the java.security file will disable features exploited by Poodle, RC4 (Bar Mitzvah), and logjam vulnerabilities.

The java.security file must be updated on the client side with the DH keySize so that is it not vulnerable to the logjam attack. Although WebSphere Application Server has disabled these ciphers and protocols by default, having RC4 and SSLv3 disabled in the java.security file is good practice since it will stop any attempt at using these.

For V3.0.9 Windows
Apply the following fix:

• IBM i2 Intelligence Analysis Platform 3.0.9 Fix Pack 1 Windows Download

For V3.0.9 Linux
Apply the following fix:

• IBM i2 Intelligence Analysis Platform 3.0.9 Fix Pack 1 Linux Download

Workarounds and Mitigations

The Logjam attack which affects TLS connections using the Diffie-Hellman (DH) key exchange protocol may affect some configurations in WebSphere Application Server.

Refer to the ‘Workarounds and Mitigations’ section of the IBM WebSphere Application Server security bulletin for full details of available workarounds and mitigations:
<http://www-01.ibm.com/support/docview.wss?uid=swg21957980&gt;