Security Bulletin
Summary
There is a vulnerability in IBM® SDK Java™ Technology Edition, Version 6 and 7, that is used by IBM OS Images for Red Hat Linux Systems, IBM OS Images for AIX, and Windows. The issue was disclosed as part of the IBM Java SDK updates in January 2016 and this vulnerability is commonly referred to as “SLOTH”.
Vulnerability Details
CVEID: CVE-2015-7575
DESCRIPTION: The TLS protocol could allow weaker than expected security caused by a collision attack when using the MD5 hash function for signing a ServerKeyExchange message during a TLS handshake. An attacker could exploit this vulnerability using man-in-the-middle techniques to impersonate a TLS server and obtain credentials. This vulnerability is commonly referred to as “SLOTH”.
CVSS Base Score: 7.1
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/109415 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/UI:U/C:H/I:L/A:N)
Affected Products and Versions
IBM OS Image for Red Hat Linux Systems 3.0.0.0 and earlier.
IBM OS Image for AIX Systems 2.1.1.0 and earlier.
Remediation/Fixes
Virtual machines deployed from IBM PureApplication Systems are affected. This includes RedHat Linux, AIX-based, and Windows-based deployments. The solution is to apply the following IBM PureApplication System fix to the deployed virtual machines.
Java Update for Windows
http://www-933.ibm.com/support/fixcentral/swg/selectFixes?parent=PureSystems&product=ibm/WebSphere/PureApplication+System&platform=All&function=fixId&fixids=Java_Update_Windows_Feb_2016
Java Update for Linux
http://www-933.ibm.com/support/fixcentral/swg/selectFixes?parent=PureSystems&product=ibm/WebSphere/PureApplication+System&platform=All&function=fixId&fixids=Java_Update_Linux_Feb_2016
Java Update for AIX
http://www-933.ibm.com/support/fixcentral/swg/selectFixes?parent=PureSystems&product=ibm/WebSphere/PureApplication+System&platform=All&function=fixId&fixids=Java_Update_AIX_Feb_2016
1. Import the fix into the Emergency Fix catalogue.
2. For deployed instances, apply this emergency fix on the VM.
3. Restart the deployed instance after the fix is applied.
Workarounds and Mitigations
For CVE-2015-7575:
Users of Java 7 and later can address the issue by updating the /jre/lib/security/java.security file as follows (both steps are required):
· Add MD5 to the jdk.certpath.disabledAlgorithms property - e.g. jdk.certpath.disabledAlgorithms=MD2, RSA keySize < 1024, MD5
· Add MD5withRSA to the jdk.tls.disabledAlgorithms property - e.g. jdk.tls.disabledAlgorithms=SSLv3, RC4, DH keySize < 768, MD5withRSA
Java 6 requires code changes in the JSSE component in addition to the java.security file modifications, so upgrading the JDK is the only solution.
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References
Acknowledgement
CVE-2015-7575 was reported to IBM by Karthikeyan Bhargavan at INRIA in Paris, France
Change History
26 February 2016: 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
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:
15 June 2018
UID
swg21977880