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Security Bulletin: Vulnerabilities in OpenSSL including Logjam affect IBM Tivoli Netcool System Service Monitors/Application Service Monitors (CVE-2015-1788, CVE-2015-1791, CVE-2015-4000)

Security Bulletin


Summary

OpenSSL vulnerabilities were disclosed on June 11, 2015 by the OpenSSL Project. This includes Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol (CVE-2015-4000). OpenSSL is used by IBM Tivoli Netcool System Service Monitors/Application Service Monitors. IBM Tivoli Netcool System Service Monitors/Application Service Monitors has addressed the applicable CVEs.

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)

CVEID: CVE-2015-1788
DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by an error when processing an ECParameters structure over a specially crafted binary polynomial field. A remote attacker could exploit this vulnerability to cause the application to enter into an infinite loop.
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/#/vulnerabilities/103778 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P)

CVEID: CVE-2015-1791
DESCRIPTION: A double-free memory error in OpenSSL in the ssl3_get_new_session_ticket() function has an unknown impact. By returning a specially crafted NewSessionTicket message, an attacker could cause the client to reuse a previous ticket resulting in a race condition.
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/#/vulnerabilities/103609 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:P/A:N)

Affected Products and Versions

SSM 4.0.0 FP1 - FP14 and Interim Fix 14-01 – Interim Fix 14-06
SSM 4.0.1 FP1 – FP2 Interim Fix 02

Remediation/Fixes

Product VRMF APAR Remediation/First Fix
4.0.1.2-TIV-SSM-IF0003 4.0.1.2 None http://www-01.ibm.com/support/docview.wss?uid=isg400002351
4.0.0.14-TIV-SSM-IF0007 4.0.0.14 None http://www-01.ibm.com/support/docview.wss?uid=isg400002356

For CVE-2015-4000: As the length of the server key size are increased, the amount of CPU required for full TLS/SSL handshake can significantly increase. Please carefully test and assess the impact to your CPU requirements to ensure sufficient CPU resources, otherwise the system availability may be impacted.

For CVE-2015-4000: 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.

Note: A fix for CVE-2014-8176 was provided in OpenSSL versions 0.9.8za, 1.0.0m, and 1.0.1h.

Workarounds and Mitigations

For CVE-2015-4000: Modify the INIVAR FileTransferSSLCipherSuite in init.cfg. This is currently:

FileTransferSSLCipherSuite=AES:3DES:DES:!EXP

Disable the DHE and EDH Ciphers by changing it to the following and restarting SSM:


FileTransferSSLCipherSuite=AES:3DES:DES:!EXP:!DHE:!EDH

Note that as this is a new INIVAR this mitigation requires applying either of the following fixes first:
SSM 4.0.1.2 Interim Fix 2 - http://www.ibm.com/support/docview.wss?uid=isg400002115
SSM 4.0.0.14 Interim Fix 6 - http://www.ibm.com/support/docview.wss?uid=isg400002120

For CVE-2015-4000: 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

Related information

Acknowledgement

Reported to IBM by The WeakDH team at https://weakdh.org

Change History

2 Oct 2015 Original Version 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.

Document information

More support for: Netcool/System Service Monitor
Netcool System Service Monitor

Software version: 4.0

Operating system(s): Platform Independent

Reference #: 1960041

Modified date: 05 October 2015