Security Bulletin: Vulnerabilities in OpenSSL including Logjam affect Rational Application Developer for WebSphere Software (CVE-2015-4000, CVE-2015-1793)

Summary

OpenSSL vulnerabilities were disclosed by the OpenSSL Project and affect Rational Application Developer for WebSphere Software. This includes the Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol (CVE-2015-4000). This also includes the alternate chains certificate forgery vulnerability (CVE-2015-1793). Rational Application Developer for WebSphere Software 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-2015-1793** **
DESCRIPTION: OpenSSL could allow a remote attacker to bypass security restrictions, caused by an implementation error of the alternative certificate chain logic. An attacker could exploit this vulnerability to bypass the CA flag and other specific checks on untrusted certificates and issue an invalid certificate.
CVSS Base Score: 7.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/104500 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)

Affected Products and Versions

IBM Rational Application Developer for WebSphere Software 9.1, 9.1.0.1, and 9.1.1

Remediation/Fixes

Update the IBM SDK for Node.js using by the Cordova platform in the product to address this vulnerability:

• Apply IBM SDK for Node.js Version 1.1 release updated equivalent to the Joyent Node.js API version 0.10.40 to the Cordova platform in the product.

Installation instructions for applying the update to the Cordova platform in the product can be found here:

Upgrading the IBM SDK for Node.js used by Cordova

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.
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

None