SOL15882 - TLS1.x padding vulnerability CVE-2014-8730

2 If you are planning to upgrade to BIG-IP APM 11.4.1 HF6 or 11.5.1 HF6 to mitigate this issue, you should instead upgrade to 11.4.1 HF7 or 11.5.1 HF7 to avoid an issue specific to BIG-IP APM. For more information, refer to SOL15914: The TMM process may restart and produce a core file after BIG-IP APM systems are upgraded.  Â

Note: Testing tools for SSL/TLS may report false positives for BIG-IP 10.2.4 HF10 and 11.2.1 HF13 due to an issue being tracked in ID 500688. While these versions have been patched and contain the code fix for CVE-2014-8730, certain test tools may still report a false positive. This reason for this is because the BIG-IP system silently terminates the connection instead of responding with abad_record_macalert. Therefore, certain test tools erroneously report a false positive because the connection times out and the tools do not receive abad_record_mac alert.

Vulnerability Recommended Actions

If the previous table lists a version in the Versions known to be not vulnerable column, you can eliminate this vulnerability by upgrading to the listed version. If the listed version is older than the version you are currently running, or if the table does not list any version in the column, then no upgrade candidate currently exists.

F5 is responding to this vulnerability as determined by the parameters defined in SOL4602: Overview of the F5 security vulnerability response policy.

To mitigate this vulnerability, you can configure a custom cipher string for the SSL profile and associate the profile with the virtual servers. To do so, perform one of the following procedures:

BIG-IP SSL profiles

To mitigate this vulnerability, you can create a custom cipher string for the SSL profile that uses RC4 or AES-GCM ciphers. For details about how to add this, refer to the following procedures:

BIG-IP 11.5.0 and later

In BIG-IP 11.5.0 and later, you can create a custom cipher string for the SSL profile using the AES-GCM:RC4-SHA ciphers. To do so, perform the following procedure:

Impact of procedure: Clients that do not support the AES-GCM or RC4-SHA ciphers will fail to establish a connection to the virtual server. RC4 ciphers are not FIPS compliant.

1. Log in to the Traffic Management Shell (tmsh)****by typing the following command:

tmsh

2. Create a custom SSL profile that specifies the AES-GCM:RC4-SHA ciphers by using the following syntax:

create /ltm profile <client-ssl / server-ssl> <profile_name> ciphers !SSLv3:AES-GCM:RC4-SHA

For example, the following command creates a custom client SSL profile called TLS-Padding:

create /ltm profile client-ssl TLS-Padding ciphers !SSLv3:AES-GCM:RC4-SHA

3. Save the configuration by typing the following command:

save /sys config

4. Associate the SSL profile with the virtual servers.

BIG-IP 10.x - 11.4.1

In BIG-IP 10.x - 11.4.1, you can create a custom cipher string for the SSL profile using the RC4-SHA ciphers. To do so, perform the following procedure:

Impact of procedure: Clients that do not support the RC4-SHA cipher will fail to establish a connection to the virtual server. RC4 ciphers are not FIPS compliant.

1. Log in to the Traffic Management Shell (tmsh)****by typing the following command:

tmsh

2. Create a custom SSL profile that specifies the RC4-SHA ciphers by using the following syntax:

create /ltm profile <client-ssl / server-ssl> <profile_name> ciphers !SSLv3:RC4-SHA

For example, the following command creates a custom client SSL profile called TLS-Padding:

create /ltm profile client-ssl TLS-Padding ciphers !SSLv3:RC4-SHA

3. Save the configuration by typing the following command:

save /sys config

4. Associate the SSL profile with the virtual servers.

Supplemental Information

• CVE-2014-3566 POODLE vs CVE-2014-8730 TLS POODLE**

Note**: A DevCentral login is required to access this content.

• SOL15702: SSLv3 vulnerability CVE-2014-3566

• SOL9970: Subscribing to email notifications regarding F5 products

• SOL9957: Creating a custom RSS feed to view new and updated documents

• SOL4918: Overview of the F5 critical issue hotfix policy

• SOL167: Downloading software and firmware from F5

• SOL13123: Managing BIG-IP product hotfixes (11.x - 12.x)

• SOL10025: Managing BIG-IP product hotfixes (10.x)

• SOL9502: BIG-IP hotfix matrix

• SOL13171: Configuring the cipher strength for SSL profiles (11.x)

• SOL7815: Configuring the cipher strength for SSL profiles (9.x - 10.x)