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Security Bulletin: Vulnerability in IBM Domino Web Server TLS AES GCM Nonce Generation

Security Bulletin


For very large data sets, IBM Domino Web servers 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 Domino 9.0.1 Fix Pack 3 Interim Fix 2 through 9.0.1 Fix Pack 5 Interim Fix 1

NOTE: Since this vulnerability involves TLS 1.2, neither IBM Domino 9.0 nor IBM Domino 8.5.x are affected.


The IBM Domino AES GCM weak nonce generation vulnerability is tracked as SPR KLYHA6ZP4F and a fix is introduced in Domino 9.0.1 FP5 Interim Fix 2..

For fix download links, refer to the following technote:

Customers who remain on the following releases may open a Service Request with IBM Support and reference SPR KLYHA6ZPF4 for a custom hotfix:
  • IBM Domino 9.0.1 Fix Pack 3 IF2 (and later IFs)
  • IBM Domino 9.0.1 Fix Pack 4 (and all IFs)

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. Refer to 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 Domino

Software version:,,

Operating system(s): AIX, Linux, Windows

Reference #: 1979604

Modified date: 28 March 2016