iRule to stop SSLv3 connections
The below iRule written by my team will stop all SSLv3 connections. If you are not using the SSL termination capabilities of your BIG-IP and instead are doing TCP load balancing, then the iRule will protect your servers from the POODLE attack.
If you are doing SSL termination at the BIG-IP, then follow the instructions in the previous article .
Please be sure to test this thoroughly in your production environment. Be sure to check any embedded devices or dedicated devices that might have older legacy software installed.
############################################## # Name: stop_ssl3 iRule # Description: This irule will reject any attempt to connnect using # an SSL3 or lower client. # VERSION: 3 - 16.oct.14 ############################################## when SERVER_CONNECTED { set Debug 1 set Collect_Len 3 TCP::collect $Collect_Len } when SERVER_DATA { set Buf_Len [TCP::offset] if { $Buf_Len < 3 } { incr Collect_Len -$Buf_Len TCP::collect $Collect_Len return } binary scan [TCP::payload] cS Rec_Type Version if { $Version <= 768 } { log local0. "stop_ssl3: Rejecting SSL3 or lower connection attempt from [IP::client_addr]" reject } else { TCP::release } }
Updated Mar 18, 2022
Version 2.0Jeff_Costlow_10
Historic F5 Account
Joined January 26, 2005
- BBDNA_8471Nimbostratus@ccna55 I have gone ahead and cleaned this up and posted to pastebin as some had suggested. Thank you very much for this! http://pastebin.com/nFnyc6iG