Security Bulletin
Summary
The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects Rational Tau
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
4.3, 4.3.0.1, 4.3.0.2, 4.3.0.3, 4.3.0.4, 4.3.0.5, 4.3.0.6, 4.3.0.6 Interim Fix 1, 4.3.0.6 Interim Fix 2, 4.3.0.6 Interim Fix 3
Remediation/Fixes
Upgrade to Rational Tau Interim Fix 4 for 4.3.0.6
Workarounds and Mitigations
No workarounds
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References
Acknowledgement
Reported to IBM by The WeakDH team at https://weakdh.org
Change History
19.06.2015: Original version publishe
*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
Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.
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Document Information
Modified date:
17 June 2018
UID
swg21960373