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Security Bulletin: Vulnerability in IBM Client Application Access TLS AES GCM Nonce Generation (CVE-2016-0270)

Security Bulletin


For very large data sets, IBM Client Application Access using TLS and AES GCM generate a weak nonce.

Vulnerability Details

CVEID: CVE-2016-0270

IBM Domino contains an unspecified vulnerability that could lead to session snooping using man-in-the-middle techniques.

Affected Products and Versions

IBM Client Application Access and IF 1 are affected.


The IBM Client Application Access AES GCM weak nonce generation vulnerability is tracked as SPR KLYHA6ZP4F and the fix is available in Interim Fix 2.

Product Version Link
IBM Client Application Access Interim Fix 2

Workarounds and Mitigations

IBM recommends that the fix be applied to relevant systems.

Customers can work around this issue by excluding AES GCM from the ciphers used by TLS 1.2. Please see the following link for instructions on configuring TLS 1.2 Ciphers

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Related information


This vulnerability was reported to IBM by Hanno Bock ( and Aaron Zauner (SBA Research).

*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.


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.

Document information

More support for: IBM Notes

Software version:

Operating system(s): OS X, Windows

Reference #: 1979673

Modified date: 31 March 2016