Security Bulletin: Vulnerability in IBM Notes TLS AES GCM Nonce Generation (CVE-2016-0270)
For very large data sets, IBM Notes using TLS and AES GCM generate a weak nonce.
DESCRIPTION: IBM Domino contains an unspecified vulnerability that could lead to session snooping using man-in-the-middle techniques.
CVSS Base Score: 5.9
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/111050 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)
Affected Products and Versions
IBM Notes 9.0.1 FP3 IF 3 and later releases. Earlier releases are not affected.
The IBM Notes AES GCM weak nonce generation vulnerability is tracked as SPR KLYHA6ZP4F and fixes are available as follows. (Note: For Domino-specific information, see technote 1979604.)
Fix introduced in
For fix download links, refer to:
Customers who remain on the following releases may open a Service Request with IBM Support and reference SPR KLYHA6ZPF4 for a custom hotfix:
- IBM Notes 9.0.1 Fix Pack 3 IF3 (and later IFs)
- IBM Notes 9.0.1 Fix Pack 4 (and all IFs)
- IBM Notes 9.0.1 Fix Pack 5 (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. Please see the following link for instructions on configuring TLS 1.2 Ciphers
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This vulnerability was reported to IBM by Hanno Bock ( https://hboeck.de/) 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.