Port 3333Network Caller ID

Port 3333 is commonly used for the Network Caller ID (NCID) server service, an open-source system designed to distribute caller identification info across a network. It enables sharing caller ID information from a telephony input (like a modem or VoIP gateway) to various connected devices, such as PCs or media centers, enhancing call screening and logging across networked systems..

transport
tcp

single transport

in transit
cleartext

payload readable on path

assignment
unofficial

used by convention

risk
4/10

caution

lookups
10,132

rank 454 of 993 · top 46%

Technical Details

what runs on :3333

Network Caller ID (NCID) is an open-source client-server architecture designed to capture and distribute caller identification information across a local network. The NCID server typically listens on TCP port 3333, receiving incoming call data from modems or telephony gateways capable of forwarding caller ID signals. Once captured, this information is disseminated to multiple NCID clients connected over the network.

The server parses the caller ID data, which may include the caller's phone number, name, and call timestamp. Clients display this information to end users in real time, facilitating network-wide call monitoring. The NCID protocol is plaintext-based and lightweight, making implementation straightforward for various platforms including Linux, Windows, macOS, and embedded devices.

Integration with other software components such as media centers or home automation systems is typical; for example, to pause media playback on incoming calls or log call histories automatically. Since communication is unencrypted by default, deployments are most secure within trusted, private networks.

Security Information

exposure of :3333

risk score

4/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

network services averages 3.9 across 604 ports — this one sits 0.1 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

unofficial

used by convention, not registered — what answers here varies by deployment

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

Common Vulnerabilities:

  • Lack of encryption exposes caller ID data to eavesdropping if operated on untrusted networks.
  • Unauthorized access could allow an attacker to inject false caller ID information or harvest call metadata.
  • Weak access controls or outdated server software may be susceptible to DoS attacks or exploitation of implementation flaws.

Common Mitigations:

  • Deploy NCID servers strictly within trusted and secured private networks.
  • Implement network segmentation or firewall rules restricting access to port 3333.
  • Consider tunneling NCID traffic through encrypted channels (such as SSH or VPN).
  • Regularly update NCID software to address security vulnerabilities.
  • Monitor logs and network activity to detect unauthorized attempts to connect to the server.

the 8 most looked-up other ports in network services — 604 ports carry that label.

risk mix of the 8 listed

  • caution100%

0 of 8 encrypted