Security Bulletin
Summary
The LogJam Attack on Diffie-Hellman ciphers (CVE-2015-4000) may affect some configurations of IBM WebSphere Application Server Full Profile that is shipped as a component of WebSphere Process Server. The IBM HTTP Server used by WebSphere Application Server is not affected.
Vulnerability Details
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
- WebSphere Process Server V7.0
- WebSphere Process Server Hypervisor Editions V6.2, V7.0
As previously announced, support for WebSphere Process Server ended 2015-04-30. WebSphere Process Server Hypervisor Editions are still in support until 2015-09-30. IBM recommends upgrading to a fixed, supported product, such as IBM Business Process Manager Advanced Edition.
Remediation/Fixes
The following setting in java.secruity allows you to reenable ciphers using DH and DHE key exchange that you had to disable as a temporary workaround:
jdk.tls.disabledAlgorithms=SSLv3, RC4, DH keySize <768
Workarounds and Mitigations
Get Notified about Future Security Bulletins
Important Note
IBM strongly suggests that all System z customers be subscribed to the System z Security Portal to receive the latest critical System z security and integrity service. If you are not subscribed, see the instructions on the System z Security web site. Security and integrity APARs and associated fixes will be posted to this portal. IBM suggests reviewing the CVSS scores and applying all security or integrity fixes as soon as possible to minimize any potential risk.
References
Acknowledgement
Reported to IBM by The WeakDH team at https://weakdh.org
Change History
2015-06-03: Original Version Published
2015-06-26: explaining new Java setting replacing the workaround
*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.
Was this topic helpful?
Document Information
Modified date:
15 September 2022
UID
swg21959105