SOL34250741 - BIND vulnerability CVE-2015-8000

Vulnerability Recommended Actions

If you are running a version listed in theVersions known to be vulnerable column, you can eliminate this vulnerability by upgrading to a version listed in theVersions known to be not vulnerable column. If the table lists only an older version than what you are currently running, or does not list a non-vulnerable version, then no upgrade candidate currently exists.

To mitigate this vulnerability, you must disable the use of recursion in the BIND configuration. You can perform the following procedures to determine if recursion has been manually enabled, and disable it if it has been enabled.

Determining if recursion has been manually enabled on the system

Impact of action: Performing the following procedure should not have a negative impact on your system.

1. Log in to the BIG-IP command line.
2. Type the following command:

grep recursion /var/named/config/named.conf

3. If the command returns the following response, recursion has been enabled, and you should perform the following, Mitigating the vulnerability procedure.

recursion yes;

If the command returns the following response, recursion has not been enabled, and the system is not vulnerable.

recursion no;

Mitigating the vulnerability

To mitigate this vulnerability, you can turn recursion off in the named.conf file. To do so, perform the following procedure:

Impact of action: This modification requires a change to your configuration. F5 recommends that you test the modified configuration in an appropriate environment before implementing it.

1. Log in to the BIG-IP command line.
2. Change directories to the /var/named/configdirectory by typing the following command:

cd /var/named/config

3. Create a backup of the named.conf file by typing the following command:

cp named.conf named.conf.SOL34250741

4. To edit the named.conf file, locate the** recursion** option.
   For example:

recursion yes;

5. Change the recursion option to** no.**
   For example:

recursion no;

6. Save the changes to the named.conf file.
7. Restart namedto allow the changes to reload by typing the following command:

bigstart restart named

Supplemental Information

• SOL9970: Subscribing to email notifications regarding F5 products
• SOL9957: Creating a custom RSS feed to view new and updated documents
• SOL4602: Overview of the F5 security vulnerability response policy
• SOL4918: Overview of the F5 critical issue hotfix policy
• SOL167: Downloading software and firmware from F5