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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2015.1534 Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects IBM Support Assistant Team Server (CVE-2015-4000) 12 June 2015 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: IBM Support Assistant Publisher: IBM Operating System: AIX Linux variants Windows Impact/Access: Access Privileged Data -- Remote/Unauthenticated Provide Misleading Information -- Remote/Unauthenticated Resolution: Mitigation CVE Names: CVE-2015-4000 Reference: ESB-2015.1470 ESB-2015.1469 ESB-2015.1466 ESB-2015.1463 ESB-2015.1455 ESB-2015.1454 ESB-2015.1453 ESB-2015.1452 ESB-2015.1445 ESB-2015.1443 ESB-2015.1432 ESB-2015.1425 Original Bulletin: http://www-01.ibm.com/support/docview.wss?uid=swg21959500 - --------------------------BEGIN INCLUDED TEXT-------------------- Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects IBM Support Assistant Team Server (CVE-2015-4000) Security Bulletin Document information More support for: IBM Support Assistant Team Server Software version: 5.0, 5.0.1.0, 5.0.1.1, 5.0.2.0 Operating system(s): AIX, Linux, Windows Software edition: TeamServer Reference #: 1959500 Modified date: 2015-06-10 Summary The Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol affects IBM Support Assistant 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 IBM Support Assistant Team Server version 5.0.0, 5.0.1, 5.0.1.1 and 5.0.2 Remediation/Fixes none Workarounds and Mitigations The Logjam attack which affects TLS connections using the Diffie-Hellman (DH) key exchange protocol may affect the IBM Support Assistant. The IBM WebSphere Application Server Liberty shipped with IBM Support Assistant has DH and DHE ciphers included in the "STRONG" or "HIGH", "MEDIUM" and "LOW" cipher lists. They also could be present if you have a "CUSTOM" list of ciphers. 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 IBM Support Assistant SSL configuration. 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. To change the list of enabled ciphers: 1. Open a command prompt, then change directory to the <isa_install>/ISA5/wlp/usr/servers/isa directory. 2. Open the server.xml file with a text editor. 3. Add the enabledCiphers attribute with the list of ciphers. See IBM SDK Cipher suites Knowledge Center for more information on the IBM SDK Java Technology Edition ciphers that are supported For additional details on how to change the configuration refer to the Liberty Profile: SSL Configuration attributes Knowledge Center Refer to the Security Bulletin for WebSphere Application Server Liberty Profile for additional details. You should verify applying this configuration change does not cause any compatibility issues. Not disabling the DH or DHE stream ciphers will expose yourself to the Logjam 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. 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 10 June 2015: original document published *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. 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It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). 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