Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects multiple IBM Rational products based on IBM Jazz technology (CVE-2015-4000)

Summary

The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects the following IBM Jazz Team Server based Applications: Collaborative Lifecycle Management (CLM), Rational Requirements Composer (RRC), Rational DOORS Next Generation (RDNG), Rational Engineering Lifecycle Manager (RELM), Rational Team Concert (RTC), Rational Quality Manager (RQM), Rational Rhapsody Design Manager (Rhapsody DM), and Rational Software Architect (RSA DM).

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

Rational Collaborative Lifecycle Management 3.0.1 - 6.0

Rational Quality Manager 2.0 - 2.0.1
Rational Quality Manager 3.0 - 3.0.1.6
Rational Quality Manager 4.0 - 4.0.7
Rational Quality Manager 5.0 - 5.0.2
Rational Quality Manager 6.0

Rational Team Concert 2.0 - 2.0.0.2
Rational Team Concert 3.0 - 3.0.6
Rational Team Concert 4.0 - 4.0.7
Rational Team Concert 5.0 - 5.0.2
Rational Team Concert 6.0

Rational Requirements Composer 2.0 - 2.0.0.4
Rational Requirements Composer 3.0 - 3.0.1.6
Rational Requirements Composer 4.0 - 4.0.7

Rational DOORS Next Generation 4.0 - 4.0.7
Rational DOORS Next Generation 5.0 - 5.0.2
Rational DOORS Next Generation 6.0

Rational Engineering Lifecycle Manager 1.0- 1.0.0.1
Rational Engineering Lifecycle Manager 4.0.3 - 4.0.7
Rational Engineering Lifecycle Manager 5.0 - 5.0.2
Rational Engineering Lifecycle Manager 6.0

Rational Rhapsody Design Manager 3.0 - 3.0.1
Rational Rhapsody Design Manager 4.0 - 4.0.7
Rational Rhapsody Design Manager 5.0 - 5.0.2
Rational Rhapsody Design Manager 6.0

Rational Software Architect Design Manager 3.0 - 3.0.1
Rational Software Architect Design Manager 4.0 - 4.0.7
Rational Software Architect Design Manager 5.0 - 5.0.2
Rational Software Architect Design Manager 6.0

Remediation/Fixes

If your product is deployed on IBM WebSphere® Application Server (WAS), you should apply the WAS remediation/mitigation according to the bulletin published by WAS:

Security Bulletin: Vulnerability with Diffie-Hellman ciphers may affect IBM WebSphere Application Server (CVE-2015-4000)

If your product is deployed on Apache Tomcat, apply the workarounds listed in the Workaround and Mitigation section.

Update your supplied IBM® Java SDK according to

Security Bulletin: Multiple vulnerabilities in IBM® Java SDK affects multiple IBM Rational products based on IBM Jazz technology (CVE-2015-0488, CVE-2015-0478, CVE-2015-2808, CVE-2015-1916, CVE-2015-0204, CVE-2015-2613, CVE-2015-2601, etc.)

Workarounds and Mitigations

If your product is deployed on IBM WebSphere® Application Server (WAS), you should apply the WAS remediation/mitigation according to the bulletin published by WAS:

Security Bulletin: Vulnerability with Diffie-Hellman ciphers may affect IBM WebSphere Application Server (CVE-2015-4000)

To disable vulnerable ciphers on Tomcat:

1. Open the file <JTS Install>/server/tomcat/conf/server.xml

2. Modify the <Connector> element, ciphersproperty to use this list:
   ciphers = "SSL_DHE_RSA_WITH_AES_128_CBC_SHA,SSL_DHE_DSS_WITH_AES_256_CBC_SHA,SSL_DHE_RSA_WITH_AES_256_CBC_SHA,SSL_DHE_RSA_WITH_AES_128_CBC_SHA256,SSL_DHE_DSS_WITH_AES_128_CBC_SHA256,SSL_DHE_RSA_WITH_AES_256_CBC_SHA256,SSL_DHE_RSA_WITH_AES_128_GCM_SHA256,SSL_DHE_DSS_WITH_AES_128_GCM_SHA256,SSL_ECDHE_RSA_WITH_AES_128_CBC_SHA,SSL_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,SSL_ECDHE_RSA_WITH_AES_256_CBC_SHA,SSL_ECDHE_RSA_WITH_AES_128_GCM_SHA256,SSL_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384,SSL_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,SSL_ECDHE_RSA_WITH_AES_128_CBC_SHA256,SSL_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,SSL_ECDHE_RSA_WITH_AES_256_CBC_SHA384,SSL_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,SSL_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_DSS_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_DSS_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_256_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_DSS_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA"

Note: To be able to use the 256 bit AES Ciphers, it may be necessary to install the JCE Unlimited Strength Jurisdiction Policy Files, which can be found here. Your IBM JRE may already have these policy files depending on version.

To disable vulnerable ciphers in the RTC Client, either:

• Disabling DH and DHE cipher suites. The can be achieved by adding the DH and DHE cipher suites to the list of disabled algorithms defined by the jdk.tls.disabledAlgorithmssecurity property in <RTC Client>/client/eclipse/jdk/jre/lib/security/java.security

Or

• Configure SP800-131a strict compliance or any Suite B configuration
• To disable vulnerable ciphers on Liberty:

1. Open the file <JTS Install>/server/liberty/clmServerTemplate/server.xml

2. Add the following line depending on the scenario used:

Case 1: Configuration when not integrating with DOORS v9.x
<ssl id="defaultSSLConfig" sslProtocol="TLS" enabledCiphers= "SSL_DHE_RSA_WITH_AES_128_CBC_SHA SSL_DHE_DSS_WITH_AES_256_CBC_SHA SSL_DHE_RSA_WITH_AES_256_CBC_SHA SSL_DHE_RSA_WITH_AES_128_CBC_SHA256 SSL_DHE_DSS_WITH_AES_128_CBC_SHA256 SSL_DHE_RSA_WITH_AES_256_CBC_SHA256 SSL_DHE_RSA_WITH_AES_128_GCM_SHA256 SSL_DHE_DSS_WITH_AES_128_GCM_SHA256 SSL_ECDHE_RSA_WITH_AES_128_CBC_SHA SSL_ECDHE_ECDSA_WITH_AES_128_CBC_SHA SSL_ECDHE_RSA_WITH_AES_256_CBC_SHA SSL_ECDHE_RSA_WITH_AES_128_GCM_SHA256 SSL_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384 SSL_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 SSL_ECDHE_RSA_WITH_AES_128_CBC_SHA256 SSL_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 SSL_ECDHE_RSA_WITH_AES_256_CBC_SHA384 SSL_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 SSL_ECDHE_ECDSA_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_128_CBC_SHA TLS_DHE_DSS_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA"/>

Case 2: Configuration when integrating with DOORS v9.x (Note: DOORS 9 requires use of some ciphers not listed in Case 1. The ciphers DOORS 9 product supports may change over time. Consult your documentation for DOORS 9 releases to monitor any changes.)
<ssl id="defaultSSLConfig" sslProtocol="TLS" enabledCiphers= "SSL_DHE_RSA_WITH_AES_128_CBC_SHA SSL_DHE_DSS_WITH_AES_256_CBC_SHA SSL_DHE_RSA_WITH_AES_256_CBC_SHA SSL_DHE_RSA_WITH_AES_128_CBC_SHA256 SSL_DHE_DSS_WITH_AES_128_CBC_SHA256 SSL_DHE_RSA_WITH_AES_256_CBC_SHA256 SSL_DHE_RSA_WITH_AES_128_GCM_SHA256 SSL_DHE_DSS_WITH_AES_128_GCM_SHA256 SSL_ECDHE_RSA_WITH_AES_128_CBC_SHA SSL_ECDHE_ECDSA_WITH_AES_128_CBC_SHA SSL_ECDHE_RSA_WITH_AES_256_CBC_SHA SSL_ECDHE_RSA_WITH_AES_128_GCM_SHA256 SSL_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384 SSL_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 SSL_ECDHE_RSA_WITH_AES_128_CBC_SHA256 SSL_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 SSL_ECDHE_RSA_WITH_AES_256_CBC_SHA384 SSL_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 SSL_ECDHE_ECDSA_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_128_CBC_SHA TLS_DHE_DSS_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA SSL_RSA_WITH_3DES_EDE_CBC_SHA SSL_RSA_WITH_AES_128_CBC_SHA SSL_RSA_WITH_AES_256_CBC_SHA TLS_RSA_WITH_3DES_EDE_CBC_SHA TLS_RSA_WITH_AES_128_CBC_SHA TLS_RSA_WITH_AES_256_CBC_SHA"/>

3. Repeat steps 1 and 2 for <JTS Install>/server/liberty/servers/clm/server.xml(if exists)

Note: It will be required to install the JCE Unlimited Strength Jurisdiction Policy Files, which can be found here. Your IBM JRE may already have these policy files depending on version.