Security Bulletin: Vulnerability with Diffie-Hellman ciphers may affect Juniper EX Series Network Switches sold by IBM for use in IBM Products (CVE-2015-4000)

Vulnerability Details

Summary

The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects Juniper EX Series Network Switches sold by IBM for use in IBM Products.

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 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

• JunOS release 12.3R9 and earlier.

Remediation/Fixes:

JunOS release 12.3R10 and later.

Juniper Technical Bulletin: http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10681

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

Workarounds and Mitigations:

Refer to the Juniper Technical Bulletin for Workarounds.

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

Change History
14 July 2015: Original Copy 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.