For some time now I have been trying to get a complete and accurate list of ports needed for cpanel/whm to work. It seems to be impossible for them to come up with it so I am starting it and perhaps some people can jump in and help.
In order to only open the ports needed on a firewall it is imperative to have a complete list and not something that says "open 2080 to 2099".

Here is what I have so far:

port service protocol direction

20 ftp tcp inbound/outbound

21 ftp tcp,udp inbound/outbound

22 ssh tcp inbound

25 smtp tcp inbound/outbound

26 smtp tcp inbound/outbound
(this port is only needed to be open if the option in cpanel to run exim on port 26 is used.)

37 rdate tcp outbound

43 whois tcp outbound

53 DNS tcp/udp inbound/outbound
(inbound is only needed if you run your own public DNS server you)

80 http tcp inbound/outbound

110 pop3 tcp inbound

113 ident tcp outbound

143 imap4 tcp inbound

443 https tcp inbound

465 smtp tls/ssl tcp/udp inbound/outbound

873 rsync tcp/udp outbound

993 imap4 ssl tcp inbound

995 pop3 ssl tcp inbound

2082 cpanel tcp inbound

2083 cpanel ssl tcp inbound

2086 whm tcp inbound/(outbound for DNS cluster)

2087 whm ssl tcp inbound/(outbound for DNS cluster)

2089 cp licence tcp outbound

2095 Webmail tcp inbound

2096 Webmail SSL tcp inbound

3306 mysql tcp (only if you need to connect remotely)

6666 chat tcp inbound

9898 AIM tcp outbound


If anyone has changes or additions please let me know and I will update this.