The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects IBM Cognos Mobile app on Android.
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
IBM Cognos Mobile app on Android version 10.2.2.1.2 and earlier.
The recommended solution is to update the app to the latest version as soon as practical.
The fix has been released as part of the IBM Cognos Mobile app on Android version 10.2.2.2.1
You should verify that applying this fix does not cause any compatibility issues. The fix disables DH and DHE ciphers by default. IBM recommends that you review your entire environment to identify other areas where you have enabled the Diffie-Hellman key-exchange protocol used in TLS and take appropriate mitigation and remediation actions.
Workarounds and Mitigations
The Logjam attack which affects TLS connections using the Diffie-Hellman (DH) key exchange protocol may affect some IBM Cognos Mobile app on Android configurations. You will need to remove any of the ciphers that begin with SSL_* or TLS_* that also have DH or DHE in the name from your web server tier SSL configurations. This does NOT include ciphers that have ECDH or ECDHE in the name, these are elliptic curve Diffie-Hellman ciphers and they are not affected.
You should verify applying this configuration change does not cause any compatibility issues. If you change the default setting after applying the fix, you will expose yourself to the attack described above. IBM recommends that you review your entire environment to identify other areas where you have enabled the Diffie-Hellman key-exchange protocol used in TLS and take appropriate mitigation and remediation actions.
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Reported to IBM by The WeakDH team at https://weakdh.org
10 June 2015: Original version published
20 July 2015: Updated remediation/fixes section
*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.
15 June 2018