rabbitmq.config

%% Disable SSLv3.0 support
[
 {ssl, [{versions, ['tlsv1.2', 'tlsv1.1', tlsv1]}]},
 {rabbit, [
           {ssl_listeners, [5671]},
           {ssl_options, [{cacertfile,"/path/to/ca_certificate.pem"},
                          {certfile,  "/path/to/server_certificate.pem"},
                          {keyfile,   "/path/to/server_key.pem"},
                          {versions, ['tlsv1.2', 'tlsv1.1', tlsv1]}
                         ]}
          ]}
].

%% to verify, use openssl s_client:
%% openssl s_client -connect 127.0.0.1:5671 -ssl3
%%
%% to test with TLSv1:
%% openssl s_client -connect 127.0.0.1:5671 -tls1
%%
%% and look for the following in the output:
%% SSL-Session:
%%   Protocol  : TLSv1

Simon, Michael, just in case someone specifies {versions, [...]} for the management plugin (or other web contexts), you might want to add something like the following to rabbit_mgmt_external_stats.erl to stop it barfing with "badarg":

format_mochiweb_option(versions, V) ->
    list_to_binary(rabbit_misc:format("~w", [V]));