26 June 2015
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2015.1669 Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects Rational Tau (CVE-2015-4000) 26 June 2015 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: IBM Rational Tau Publisher: IBM Operating System: Linux variants Windows Impact/Access: Access Privileged Data -- Remote/Unauthenticated Provide Misleading Information -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2015-4000 Reference: ESB-2015.1663 ESB-2015.1655 ESB-2015.1640 ESB-2015.1623 ESB-2015.1614 ESB-2015.1611 ESB-2015.1587 Original Bulletin: http://www-01.ibm.com/support/docview.wss?uid=swg21960373 - --------------------------BEGIN INCLUDED TEXT-------------------- Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects Rational Tau (CVE-2015-4000) Document information More support for: Rational Tau Documentation Software version: 4.3, 220.127.116.11, 18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52, 184.108.40.206 Operating system(s): Linux, Windows Reference #: 1960373 Modified date: 2015-06-25 Security Bulletin This document applies only to the following language version(s): English Summary The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects Rational Tau 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 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 4.3, 220.127.116.11, 18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52, 184.108.40.206, 220.127.116.11 Interim Fix 1, 18.104.22.168 Interim Fix 2, 22.214.171.124 Interim Fix 3 Remediation/Fixes Upgrade to Rational Tau Interim Fix 4 for 126.96.36.199 Workarounds and Mitigations No workarounds Get Notified about Future Security Bulletins Subscribe to My Notifications to be notified of important product support alerts like this. References Complete CVSS Guide On-line Calculator V2 Related information IBM Secure Engineering Web Portal IBM Product Security Incident Response Blog Acknowledgement Reported to IBM by The WeakDH team at https://weakdh.org Change History 19.06.2015: Original version publishe *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 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. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to email@example.com and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. 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On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBVYzA2H6ZAP0PgtI9AQLM4g/+JEsNxnRPI3VOXU5T8FYr5Oci/eUI0Q9y LsAss/mScJa2IUvPRsdpKRtoL+r7rDl0SuXw1STn9LOQbhKd1/hEhenkVmJm4rFS y2o/hzB/7vtStepjhVZcFs+9hvhsILz/ek+HPqF5tRpGDAEpBj/1eSoMjYuto9yv e5633szDAYYFqmCzz91XHRxcShEkzzi1/05OEA6rH+whhzjnSVXZNlZdjfvutZav mNKd0ZFbYMzp0UA9+YhIsNkQi+T0Q7ZvQ6GRvccpr9s3ar/3qYT1thO6Uw5Pyh+J iH7e0oFJLSCxlEsQhkho9ACsDLZDDoFDaISQ+7e4gptZBSYTrUNZ1FEvB5iO+oVT uNKJr5FXxQItc7YkT0PvrRgWAgY7vVqrlEbv1cIZ8KwNRCu25AsXP9k2/tlwrYHz r9hWcAwgzPV11IVWsmRxznA35J/+7TVDlC7VkrABaQNdoLjfFRRmL25TGEg07JcK HN4JLusTOgBY8OZEikrTmO06mE1A/Cp+g4zEv6GescbfNuTOSNAU9pMkYXlgbmLe uX08bAkdEhvAn3QaFhIgnt8zhoXfkOcfKotoop73EPHUxRY1Ki5CPOgqdi9DaH5i yhwxNxFMFNLJ5s4OGCou869ic7isGSF9OuN9MLSvZBZELA/9gKYuoKkD4vVM68Op 9NEIZeKQjyA= =Dwt0 -----END PGP SIGNATURE-----