Port 992Telnet over TLS/SSL
Port 992 is designated for Telnet communications secured through TLS/SSL encryption, augmenting the traditional Telnet protocol by providing a secure channel that protects data integrity and confidentiality during remote command-line sessions. It is used primarily where legacy Telnet access needs to be maintained while enhancing security..
- transport
- tcp · udp
- in transit
- encrypted
- assignment
- official
- risk
- 4/10
- lookups
- 23,512
2 transports registered
payload protected on the wire
registered with iana
caution
rank 83 of 993 · top 8%
Technical Details
what runs on :992Port 992 facilitates Telnet access encapsulated within TLS/SSL, often called Secure Telnet. This configuration enables encrypted bidirectional text-based communication commonly used for remote system management, troubleshooting, and command-line interactions. Unlike Telnet on its default port 23—which transmits plaintext data including passwords—port 992 wraps all traffic inside an encrypted tunnel.
Typically, TLS negotiation occurs immediately upon connection, before credentials or commands are transmitted, mitigating the risk of interception. The implementation requires both server and client to support TLS extensions on their Telnet software. Despite being an IANA-assigned official port, support and deployment can vary across platforms.
Secure Telnet remains relevant mainly for backward-compatibility scenarios where SSH adoption may be impractical. However, protocols like SSH have largely superseded it due to better integrated security features and key management systems. Still, port 992’s capability allows organizations to enhance security without completely overhauling existing Telnet infrastructure.
Security Information
exposure of :992risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
security averages 3.8 across 216 ports — this one sits 0.2 above.
in transit
encrypted
payloads are protected on the wire
assignment
official
registered with iana for this service — scanners fingerprint it by number
reachable over
tcp · udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common vulnerabilities:
- Misconfigured TLS resulting in insecure cipher suites or outdated SSL versions
- Lack of validation leading to potential man-in-the-middle (MITM) attacks if certificates aren’t properly managed
- Legacy Telnet server flaws can persist even when encapsulated in TLS
- Possible downgrade attacks that force unencrypted sessions
Common mitigations:
- Enforce strong TLS ciphers and disable SSLv2/v3 to prevent exploitation of known weaknesses
- Use valid, trusted certificates and implement strict certificate validation on clients
- Regularly update and patch Telnet software to fix security vulnerabilities
- Restrict access using firewalls and access control lists (ACLs)
- Whenever possible, migrate to SSH, which offers a more robust security architecture with support for advanced authentication and encryption options
Related Ports
the 8 most looked-up other ports in security — 216 ports carry that label.
| port | service | risk | |||
|---|---|---|---|---|---|
| :8881 | Atlasz Secure Server | TCP | Web Services | caution | 67.6k |
| :443 | HTTPS | TCPtls | Web Services | caution | 65.9k |
| :8291 | Winbox MikroTik Admin | TCP | Security | caution | 62.9k |
| :3268 | Microsoft Global Catalog (GC) | TCPUDP | Security | caution | 54.6k |
| :135 | Microsoft EPMAP | TCPUDP | Security | caution | 51.9k |
| :3128 | Squid Proxy HTTP | TCP | Web Services | caution | 45.8k |
| :8080 | HTTP Alternate | TCPtls | Web Services | caution | 44.9k |
| :7000 | Vuze HTTPS Tracker | TCPtls | Security | caution | 28.9k |
risk mix of the 8 listed
- caution100%
3 of 8 encrypted