Common attacks and weaknesses
- Stream keys sent in clear text.
Port 1935: RTMP
Live video ingest (OBS, streaming platforms).
1935
How RTMP works
Media & streamingThe device streams video frames over port 1935, continuously, as they are captured. It travels in clear text: anyone on the path can read it.
- Transport
- TCP · UDP
- Exposure risk
- 3/10 moderate if reachable from the Internet
- Encryption
- Clear textreadable on the network
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Media & streaming
Is port 1935 dangerous?
How to secure it
- Use RTMPS (TLS).
IANA registry entries for port 1935
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| macromedia-fcs | 1935 | TCP, UDP | Macromedia Flash Communications Server MX | - | - |
// source: IANA service name and port number registry
Which program uses port 1935, and is it reachable?
Linux
sudo ss -ltnup 'sport = :1935' # process listening on 1935
sudo lsof -nP -i :1935macOS
sudo lsof -nP -i :1935
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1935 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 1935 netstat -ano | findstr :1935
From another machine
nmap -p 1935 -sV <host> sudo nmap -sU -p 1935 <host> nc -zv <host> 1935
Block it in the firewall
sudo ufw deny 1935/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 1935" -Direction Inbound -LocalPort 1935 -Protocol TCP -Action Block # Windows
What is port 1935 used for?
Live video ingest (OBS, streaming platforms).
Is port 1935 TCP or UDP?
Port 1935 is registered for TCP and UDP. In practice the service mostly uses TCP.
Is it safe to open port 1935?
It is rated 3/10 (moderate) when exposed to the Internet. Stream keys sent in clear text. Use RTMPS (TLS).
How do I check if port 1935 is open?
On Linux run "ss -ltnup 'sport = :1935'", on macOS "lsof -nP -i :1935", and on Windows "netstat -ano | findstr :1935" to see the local process. From another machine, "nmap -p 1935 <host>" shows whether it is reachable.