Port 7547 (TR-069 (CWMP))

ISP remote management of customer routers and modems (CPE WAN Management Protocol).

Registered (user) port, 1024-49151 TCP IoT and devices Expose only to trusted sources

What port 7547 is used for

ISP remote management of customer routers and modems (CPE WAN Management Protocol).

Security: should port 7547 be open?

Expose only to trusted sources. Should accept connections only from the ISP's ACS. A 2016 Mirai variant knocked about 900,000 Deutsche Telekom routers offline through a TR-064 bug on port 7547.

IANA assignment

Service nameProtoDescriptionAssigneeReference

cwmp TCP Broadband Forum CWMP Broadband Forum -

cwmp UDP Broadband Forum CWMP Broadband Forum -

Registry dates for this port: registered 2006-01, last modified 2019-12-13.

Check what is listening on port 7547

Linux: is anything listening on TCP 7547?

sudo ss -tlnp 'sport = :7547'

Linux / macOS: which process owns the port

sudo lsof -nP -i :7547

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':7547 '

Windows (Command Prompt)

netstat -ano | findstr :7547

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 7547 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 7547

From Windows

Test-NetConnection HOST -Port 7547

Allow only trusted sources on port 7547 in the firewall

Replace 203.0.113.10 with the address or network you trust. With ufw, make sure the default incoming policy is deny.

ufw (one trusted source)

sudo ufw allow from 203.0.113.10 to any port 7547 proto tcp

iptables

sudo iptables -A INPUT -p tcp --dport 7547 -s 203.0.113.10 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 7547 -j DROP

nftables

sudo nft add rule inet filter input ip saddr 203.0.113.10 tcp dport 7547 accept
sudo nft add rule inet filter input tcp dport 7547 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'TCP 7547 trusted' -Direction Inbound -Protocol TCP -LocalPort 7547 -RemoteAddress 203.0.113.10 -Action Allow

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.