Security Bulletin: Vulnerability in RC4 stream cipher affects IBM DataPower Gateway Appliances (CVE-2015-2808)

Summary

The RC4 “Bar Mitzvah” Attack for SSL/TLS affects IBM DataPower Gateway Appliances.

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 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

All DataPower products and versions that are configured to perform SSL/TLS transactions.

Remediation/Fixes

None

Workarounds and Mitigations

Disable RC4 ciphers in DataPower configuration referring to the steps below.

First make sure to Quiesce all domains and services to stop traffic to the appliance. System quiesce and unquiesce commands can be invoked by navigating to Administration –> Main –> System Control.

Next, select Objects –> Crypto Configuration –> Crypto Profile in the left navigation pane. For all the crypto profile objects that are configured, in the “Configure Crypto Profile” page, “Ciphers” parameter, suffix the existing string with a value “:!RC4”. Click Apply.

For example, if you have a default configuration, the updates will appear as below:
Default cipher string: HIGH:MEDIUM:!aNULL:!eNULL:@STRENGTH
RC4 disabled cipher string: HIGH:MEDIUM:!aNULL:!eNULL:@STRENGTH**:!RC4**

Note that RC4 must be disabled in all the Crypto Profile objects configured in all the domains.

To disable RC4 in Web Management and XML Management interfaces, refer to Disable RC4 in DataPower Web management and XML management services.

If you have configured WebSphere JMS or Tibco EMS objects, refer to Disable RC4 in DataPower WebSphere Java Message Service (JMS).

If you have configured WebSphere MQ objects, refer to Disable RC4 in DataPower MQ Queue Manager objects.

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.