Security Bulletin: Vulnerability in RC4 stream cipher affects Rational Tau (CVE-2015-2808)

Summary

The RC4 “Bar Mitzvah” Attack for SSL/TLS affects Rational Tau.

Vulnerability Details

CVEID: CVE-2015-2808

**DESCRIPTION:**The RC4 algorithm, as used in the TLS protocol and SSL protocol, could allow a remote attacker to obtain sensitive information. An attacker could exploit this vulnerability to remotely expose account credentials without requiring an active man-in-the-middle session. Successful exploitation could allow an attacker to retrieve credit card data or other sensitive information. This vulnerability is commonly referred to as “Bar Mitzvah Attack”.

CVSS Base Score: 5

CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/101851&gt; for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:P/I:N/A:N)

Affected Products and Versions

4.3, 4.3.0.1, 4.3.0.2, 4.3.0.3, 4.3.0.4, 4.3.0.5, 4.3.0.6, 4.3.0.6 Interim Fix 1, 4.3.0.6 Interim Fix 2

Remediation/Fixes

Upgrade to Rational Tau Interim Fix 3 for 4.3.0.6

Workarounds and Mitigations

You should verify applying this configuration change does not cause any compatibility issues. Not disabling the RC4 stream cipher 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 RC4 stream cipher and take appropriate mitigation and remediation actions.