## Summary
The Logjam Attack on TLS(Transport Layer Security) connections using the Diffie-Hellman (DH) key exchange protocol affects IMS Enterprise Suite: SOAP Gateway.
## 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
The SOAP Gateway component of the IMS Enterprise Suite Versions 3.1 and earlier.
## Workarounds and Mitigations
**Java 7 and Java 8 Mitigation:**
1. 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.disabledAlgorithms security property in java.security file
SSL_DHE_RSA_WITH_AES_256_CBC_SHA256
SSL_DHE_DSS_WITH_AES_256_CBC_SHA256
SSL_DHE_RSA_WITH_AES_256_CBC_SHA
SSL_DHE_DSS_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_128_CBC_SHA
SSL_DHE_DSS_WITH_AES_128_CBC_SHA
SSL_DHE_DSS_WITH_AES_256_GCM_SHA384
SSL_DHE_RSA_WITH_AES_256_GCM_SHA384
SSL_DHE_RSA_WITH_AES_128_GCM_SHA256
SSL_DHE_DSS_WITH_AES_128_GCM_SHA256
SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA
SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA
SSL_DH_anon_WITH_AES_256_GCM_SHA384
SSL_DH_anon_WITH_AES_128_GCM_SHA256
SSL_DH_anon_WITH_AES_256_CBC_SHA256
SSL_DH_anon_WITH_AES_256_CBC_SHA
SSL_DH_anon_WITH_AES_128_CBC_SHA256
SSL_DH_anon_WITH_AES_128_CBC_SHA
SSL_DH_anon_WITH_3DES_EDE_CBC_SHA
SSL_DH_anon_WITH_RC4_128_MD5
SSL_DHE_RSA_WITH_DES_CBC_SHA
SSL_DHE_DSS_WITH_DES_CBC_SHA
SSL_DH_anon_WITH_DES_CBC_SHA
SSL_DHE_DSS_WITH_RC4_128_SHA
SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA
SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA
SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA
You should verify applying this configuration change does not cause any compatibility issues. IBM recommends that you review your entire environment to identify other areas where you have enabled the Diffie-Hellman key-exchange protocol used in TLS and take appropriate mitigation and remediation actions.
**Important note: **IBM strongly suggests that all System z customers subscribe to the System z Security Portal to receive the latest critical System z security and integrity service. If you are not subscribed, see the instructions on the [_System z Security web site_](). Security and integrity APARs and associated fixes will be posted to this portal. IBM suggests reviewing the CVSS scores and applying all security or integrity fixes as soon as possible to minimize any potential risk..
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## Important Note
IBM strongly suggests that all System z customers be subscribed to the System z Security Portal to receive the latest critical System z security and integrity service. If you are not subscribed, see the instructions on the [System z Security web site](). Security and integrity APARs and associated fixes will be posted to this portal. IBM suggests reviewing the CVSS scores and applying all security or integrity fixes as soon as possible to minimize any potential risk.
### References
[Complete CVSS v2 Guide]( “Link resides outside of ibm.com” )
[On-line Calculator v2]( “Link resides outside of ibm.com” )
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## Related Information
[IBM Secure Engineering Web Portal]()
[IBM Product Security Incident Response Blog]()
*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. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. “Affected Products and Versions” referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
[{“Product”:{“code”:”SSGMWY”,”label”:”IBM IMS Enterprise Suite for z/OS”},”Business Unit”:{“code”:”BU058″,”label”:”IBM Infrastructure w/TPS”},”Component”:”SOAP Gateway”,”Platform”:[{“code”:”PF035″,”label”:”z/OS”},{“code”:”PF016″,”label”:”Linux”},{“code”:”PF033″,”label”:”Windows”}],”Version”:”2.2;3.1″,”Edition”:””,”Line of Business”:{“code”:”LOB35″,”label”:”Mainframe SW”}}]Read More