Proxmox Firewall Service Disable using Command

Chrooting and then doing:

systemctl disable pve-firewall
systemctl mask pve-firewall

should do the trick. then after rebooting and fixing your config,

systemctl unmask pve-firewall
systemctl enable pve-firewall
systemctl start pve-firewall

Should return to the defaults again.

Ports used by Proxmox VE

• Web interface: 8006 (TCP, HTTP/1.1 over TLS)
• VNC Web console: 5900-5999 (TCP, WebSocket
• SPICE proxy: 3128 (TCP)
• sshd (used for cluster actions): 22 (TCP)
• rpcbind: 111 (UDP)
• sendmail: 25 (TCP, outgoing)
• corosync cluster traffic: 5405-5412 UDP
• live migration (VM memory and local-disk data): 60000-60050 (TCP)

Ref:
https://pve.proxmox.com/wiki/Firewall
https://forum.proxmox.com/threads/how-to-disable-pve-firewall-after-lock-out-datacenter-level-firewall.60557/