Security Bulletin: Vulnerability in Diffie-Hellman ciphers affects IBM DB2 Recovery Expert for Linux, UNIX and Windows (CVE-2015-4000)

Workarounds and Mitigations

Disable the DH and DHE cipher suites by adding "DH, DHE" to the list of disabled algorithms defined by the jdk.tls.disabledAlgorithms security property in java.security file.

Edit the java.security file that is located in the Recovery Expert installation directory:

   /jre/lib/security/java.security

Add the following line and save the file:

   jdk.tls.disabledAlgorithms=DH, DHE

If the jdk.tls.disabledAlgorithms property was already enabled (without a "#" character at the beginning of the line), i.e.:

   jdk.tls.disabledAlgorithms=SSLv3

then append the text ", DH, DHE" to the end of the line and save the file.

   jdk.tls.disabledAlgorithms=SSLv3, DH, DHE

Restart the Recovery Expert server for this change to take effect.

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.