Security Bulletin: Logjam vulnerability affects IBM Flex System EN6131 40Gb Ethernet / IB6131 40Gb Infiniband Switch firmware (CVE-2015-4000)

Summary

OpenSSL vulnerabilities were disclosed on June 11, 2015 by the OpenSSL Project. This includes Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol (CVE-2015-4000). OpenSSL is used by IBM Flex System EN6131 40Gb Ethernet /IB6131 40Gb Infiniband Switch firmware. IBM Flex System EN6131 40Gb Ethernet / IB6131 40Gb Infiniband Switch firmware has addressed the applicable CVE.

Vulnerability Details

Summary

OpenSSL vulnerabilities were disclosed on June 11, 2015 by the OpenSSL Project. This includes Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol (CVE-2015-4000). OpenSSL is used by IBM Flex System EN6131 40Gb Ethernet / IB6131 40Gb Infiniband Switch firmware. IBM Flex System EN6131 40Gb Ethernet / IB6131 40Gb Infiniband Switch firmware has addressed the applicable CVE.

Vulnerability Details:

CVE-ID: 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 <http://exchange.xforce.ibmcloud.com/vulnerabilities/103294&gt; for current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:N/A:N)

Affected Products and Versions

Remediation/Fixes:

Firmware fix versions are available on Fix Central: <http://www.ibm.com/support/fixcentral/&gt;

You should verify applying the fix does not cause any compatibility issues.

For CVE-2015-4000: You should verify applying this configuration change does not cause any compatibility issues. If you change the default setting after applying the fix, you 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 Diffie-Hellman key-exchange protocol used in TLS and take appropriate mitigation and remediation actions.

Workarounds and Mitigations:

None.

References:

• Complete CVSS v2 Guide
• On-line Calculator v2

Related Information:
IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Acknowledgement

None.

Change History
04 December 2015: Original version published

• 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.