Security Bulletin
Summary
The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects IBM Tealeaf Customer Experience.
Vulnerability Details
CVEID: CVE-2015-4000
DESCRIPTION: The TLS protocol could allow a remote attacker to obtain sensitive information, caused by the failure to properly convey a DHE_EXPORT cipher suite 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 Tealeaf Customer Experience: v8.0-v9.0.2
Remediation/Fixes
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.
Workarounds and Mitigations
PCA: In addition to applying the fix pack above, you must update the /opt/tealeaf/etc/httpd.conf file, changing the line beginning “SSLCipherSuite” by adding the string “:!DHE:!EDH” so that it reads:
SSLCipherSuite ALL:!ADH:!EXP:!RC4:+HIGH:+MEDIUM:!DHE:!EDH
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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References
Acknowledgement
Reported to IBM by The WeakDH team at https://weakdh.org
Change History
09 June 2016: Update Fix Central links.
04 September 2015: Update CVSS link.
21 July 2015: Update Fix Central links.
15 July 2015: Edits and update links
24 June 2015 : Original Version
*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.
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Document Information
Modified date:
16 June 2018
UID
swg21959030