Копипаста статьи с форума DirectAdmin. Нужно установить следующие значения в указанных файлах:
Apache
/etc/httpd/conf/extra/httpd-ssl.conf
SSLProtocol All -SSLv2 -SSLv3 SSLHonorCipherOrder On SSLCipherSuite HIGH:!aNULL:!MD5
Nginx/Proxy
/usr/local/directadmin/data/templates/nginx_ips.conf
/usr/local/directadmin/data/templates/nginx_server_secure.conf
/usr/local/directadmin/data/templates/nginx_server_secure_sub.conf
/etc/nginx/directadmin-ips.conf
/etc/nginx/nginx-vhosts.conf
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
Dovecot: 2.1+
/etc/dovecot/dovecot.conf
ssl_protocols = !SSLv2 !SSLv3 ssl_cipher_list = ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:-LOW:-SSLv2:-EXP
Exim: 4.80+
/etc/exim.conf
openssl_options = +no_sslv2 +no_sslv3 tls_require_ciphers = ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:-LOW:-SSLv2:-EXP
DirectAdmin
/usr/local/directadmin/conf/directadmin.conf
Current binaries only allow TLSv1.2:
ssl_cipher=HIGH:!aNULL:!MD5
Binaries older than October 16, 2014 use this
ssl_cipher=ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:-LOW:-SSLv2:-SSLv3:-EXP
Pure-FTPd
/etc/init.d/pure-ftpd
/usr/libexec/pureftpd_startscript
OPTIONS="${OPTIONS} -Y 1 -J -S:HIGH:MEDIUM:+TLSv1:!SSLv2:+SSLv3"
ProFTPd
/etc/proftpd.conf
TLSProtocol TLSv1 TLSCipherSuite HIGH:MEDIUM:+TLSv1:!SSLv2:+SSLv3