To make a server that is running Plesk PCI compliant follow these steps:
- Turn off medium and weak ciphers on the Plesk port (8443). This is done by editing the /usr/local/psa/admin/conf/httpsd.custom.include file.
SSLProtocol -ALL +SSLv3 +TLSv1 SSLCipherSuite HIGH:!MEDIUM:!LOW:!SSLv2:!EXP:!NULL:@STRENGTH ErrorDocument 417 "Expect not supported" ErrorDocument 413 "Request Entity Too Large." ServerTokens Prod UserDir Disabled
The ErrorDocument prevents a XSS exploit using the expect headers. This must be done in the httpsd.custom.include file or else you Plesk will over write the changes. For the changes to take affect:
# /sbin/service psa stop # /sbin/service psa start
To test and make sure SSLv2 is disabled:
# openssl s_client -connect localhost:8443 -ssl2
You should not see any SSL information. To test the Expect headers:
# openssl s_client -host localhost:8443
Once you see a '---' enter the following to test:
R....snip... Get / HTTP/1.1 Host: localhost Expect: */<script>fooz</script>/*
If everything worked, you will see:
HTTP/1.1 417 Expectation Failed Date: Wed, 24 Mar 2010 21:08:32 GMT Server: Apache Transfer-Encoding: chunked Content-Type: text/html; charset=iso-8859-1 15 Expect not supported 0
- Do the same thing as you did above for Apache. Create the file /etc/httpd/conf.d/zz050-psa-disable-weak-ssl-ciphers.conf and add:
SSLProtocol -ALL +SSLv3 +TLSv1 SSLCipherSuite HIGH:!MEDIUM:!SSLv2:!LOW:!EXP:!aNULL:@STRENGTH
Apache has to be restarted for the changes to take affect:
# /sbin/service httpd restart
To test and make sure SSLv2 is disabled:
# openssl s_client -connect localhost:443 -ssl2
You should not see any SSL information.
- Moving on to IMAP and POP3, the /etc/courier-imap/imapd-ssl and
/etc/courier-imap/pop3d-ssl files need to be modified by adding the following line:TLS_CIPHER_LIST="HIGH:!ADH:RC4+RSA:!SSLv2:!LOW:!MEDIUM:@STRENGTH"
If there is another line with that variable setting, make sure you either remove it or comment it out. Restart the service:
# /sbin/service courier-imap restart
Test to make sure that SSLv2 has been properly disabled:
# openssl s_client -connect localhost:993 -ssl2 # openssl s_client -connect localhost:995 -ssl2
You should not see any SSL information.
- Turn off SSLv2 for port 465, add the following line to /var/qmail/control/tlsserverciphers and /var/qmail/control/tlsclientciphers
!ALL:!aNULL:!ADH:!eNULL:!LOW:!EXP:!SSLv2:RC4+RSA:+HIGH:!MEDIUM
Restart qmail:
# /sbin/service qmail restart
Test the new settings:# openssl s_client -connect localhost:465 -ssl2
You should not see any SSL information. - Configure named that it does not support recursion. This is done by editing the /etc/named.conf and adding the following below the options section
recursion no;
- PCI audits will fail if the certificate has expired for courier-imap. This is easily fixed. Navigate to the /usr/share/courier-imap directory and run the following commands:
# ./mkimapdcert #./mkpop3dcert
This will create a new certificate for both services resolving the issue of expired certificates. These certificates will expire in 1 year.
- Add the following to your /etc/php.ini and your /usr/local/psa/admin/conf/php.ini, this requires httpd and Plesk to be restarted:
expose_php = Off # /sbin/service httpd restart # /sbin/service psa restart
- PCI scans are starting to fail when connecting to a site via port 25 (SMTP) and 587 (submission). There is another certificate that needs to be updated. I used a self signed certificate, but you can replace the certificate with one from a respected CA:
# cd /var/qmail/control # openssl genrsa 2048 > host.key # openssl req -new -x509 -nodes -sha1 -days 730 -key host.key > host.cert # cat host.cert host.key > host.pem # cp servercert.pem > servercert.pem.bk # mv host.pem servercert.pem # /sbin/service qmail restart
To test:
$ openssl s_client -connect host.com:25 -starttls smtp $ openssl s_client -connect host.com:587 -starttls smtp
This has been written and tested on Plesk 8.6 Some of the items may be applied to later versions of Plesk.