Port 990FTPS Control
FTPS (File Transfer Protocol Secure) Control utilizes port 990 to establish an encrypted communication channel for managing connections in an FTP over TLS/SSL environment. It provides authentication and command exchange securely, protecting data integrity and confidentiality during the initiation of file transfers..
- transport
- tcp · udp
- in transit
- encrypted
- assignment
- official
- risk
- 3/10
- lookups
- 21,770
2 transports registered
payload protected on the wire
registered with iana
caution
rank 102 of 993 · top 10%
Technical Details
what runs on :990FTPS, or FTP Secure, extends the traditional File Transfer Protocol by adding SSL/TLS encryption. The control connection, which coordinates commands and responses between client and server, typically operates over port 990 in implicit mode. When a client connects to port 990, it immediately expects an encrypted SSL/TLS session, differing from explicit FTPS which negotiates encryption after an initial plaintext connection.
In implicit FTPS, all communications including authentication credentials and commands are encrypted from the beginning, offering enhanced privacy and data protection during session negotiations. This encryption ensures sensitive commands such as login credentials are not transmitted in cleartext over the network.
The FTPS control channel then facilitates negotiation of separate dynamic data connections, encrypted as well, used for the actual transfer of files. Support for both active and passive FTP modes is maintained, but both the control and data connections are secured via SSL/TLS certificates, often requiring mutual verification for enhanced security.
Security Information
exposure of :990risk score
3/ 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 0.8 below.
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 FTPS servers that accept obsolete SSL/TLS versions (e.g., SSLv2/3, TLS 1.0) are susceptible to downgrade attacks and known protocol weaknesses.
- Improper certificate validation exposes clients to Man-in-the-Middle (MitM) attacks.
- Weak cipher suites can undermine encryption strength.
- If firewalls are not properly configured, dynamic FTPS data connections may be hijacked or blocked, inadvertently causing security gaps.
Mitigations:
- Enforce strong, recent TLS versions (TLS 1.2 or TLS 1.3) and disable deprecated protocols.
- Use strong cipher suites and ensure certificates are valid, signed by trusted authorities, and regularly updated.
- Configure firewalls specifically for FTPS, enabling secure communication for control and data channels while limiting exposure.
- Employ strict server and client certificate verification to prevent impersonation.
- Monitor FTPS server logs for suspicious access attempts and enforce multi-factor authentication where possible.
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