on 14-Oct-2014 18:59
A new SSL vulnerability has been released titled POODLE (Padding Oracle On Downgraded Legacy Encryption). CVE-2014-3566 is the official reference to this vulnerability. During a TLS connection handshake, an attacker can interrupt the connection and cause a fallback to SSLv3. The connection that is now using an older, less-secure protocol is more vulnerable to other attacks due to it’s weaker encryption techniques. Disabling SSLv3 ciphers is the only known way to avoid this attack. LineRate has SSLv3 ciphers installed by default for maximum compatibility, but if you’re using HTTPS, you should follow this procedure to disable them. (Note that the use of SSLv3 has been discouraged for many years, so not many connections require or even use SSL in favor of the much more secure TLS protocol.) You might also want to check out the BIG-IP response here. See SOL15702 for more details on this vulnerability.
The LineRate Team has worked on maintenance releases to address this vulnerability and others. You can find details of the maintenance releases here. Upgrading to the new version of 2.2.7 and 2.4.2 gives you more ciphers than disabling SSLv3 ciphers using the workaround. The workaround disables some of the ciphers that work with TLS.
Please note the action required for versions of LineRate differ:
Use the following procedure to disable the SSLv3 ciphers for any configured SSL profiles. Once these ciphers are disabled, any HTTPS connections initiated or terminated by the LineRate system will be vulnerable to POODLE.
LROS# show ssl profile self-signed Configuration Primary Cert Name: self-signed set locally Private Key Name: self-signed set locally Chained Cert Name: <none> Primary Cert and Key Match: yes Cipher List: HIGH:!ADH:!SSLv2:!PSK:!ECDH:!kEDH:!SRP:+AES:+3DES default ECC Curve List: prime256v1 default SSL Session Cache Mode: no cache set locally SSL Session Cache Size: 0 set locally SSL Session Tickets Mode: enabled default Ordered cipher list AES256-GCM-SHA384 AES256-SHA256 AES256-SHA AES128-GCM-SHA256 AES128-SHA256 AES128-SHA DES-CBC3-SHA
Disable the SSLv3 ciphers using the command: cipher-list openssl "!SSLv3:HIGH:!ADH:!SSLv2:!PSK:!ECDH:!kEDH:!SRP:+AES:+3DES". This cipher list was obtained by taking the existing cipher-list from the command run in Step 2 and pre-pending “!SSLv3”. Using !, the ciphers are permanently deleted from the list. Please refer to the SSL Mode commands for more detail. Please note that this step will need to be be repeated for every SSL profile configured on the system.
LROS# configure LROS(config)# ssl profile self-signed LROS(config-ssl-profile:self-signed)# cipher-list openssl "!SSLv3:HIGH:!ADH:!SSLv2:!PSK:!ECDH:!kEDH:!SRP:+AES:+3DES"
*LROS(config-ssl-profile:self-signed)# show ssl profile self-signed Configuration Primary Cert Name: self-signed set locally Private Key Name: self-signed set locally Chained Cert Name: <none> Primary Cert and Key Match: yes Cipher List: !SSLv3:HIGH:!ADH:!SSLv2:!PSK:!ECDH:!kEDH:!SRP:+AES:+3DES set locally ECC Curve List: prime256v1 default SSL Session Cache Mode: no cache set locally SSL Session Cache Size: 0 set locally SSL Session Tickets Mode: enabled default Ordered cipher list AES256-GCM-SHA384 AES256-SHA256 AES128-GCM-SHA256 AES128-SHA256
*LROS# write
LROS 2.4 CLI Reference Guide SSL Mode Commands - cipher-list
LROS 2.4 REST API Reference Guide - cipherListOpenSslFormat