Is port 21 (FTP Control) dangerous?

Port 21 is classified as critical risk and should not be exposed to the public internet. It transmits data without encryption, making it vulnerable to eavesdropping and credential theft.

Should port 21 be open on my firewall?

No, port 21 should not be open to the public internet. Block it at the firewall and use encrypted alternatives such as SSH, SFTP, or HTTPS instead.

What transport protocol does port 21 use?

Port 21 (FTP Control) uses the TCP transport protocol and falls under the File Transfer category.

:21 (TCP)

FTP Control

Critical Risiko

TCP — File Transfer

Ikhtisar Port

Nomor Port 21

Nama Layanan FTP Control

Protokol Transport TCP

Kategori File Transfer

Risiko Keamanan Critical

Rentang Port Well-Known (0-1023)

Apa itu Port 21?

FTP control channel. Handles authentication, directory listing commands, and file transfer negotiation. Sends usernames and passwords in plaintext.

TCP File Transfer Umum Digunakan

Pertimbangan Keamanan

Port 21 (FTP Control) diklasifikasikan sebagai risiko kritis. Port ini tidak boleh diekspos ke internet publik. Layanan ini mentransmisikan data tanpa enkripsi, sehingga rentan terhadap penyadapan, pencurian kredensial, dan serangan man-in-the-middle.

Rekomendasi: Blokir port ini di firewall. Gunakan alternatif terenkripsi (SSH, SFTP, HTTPS) sebagai gantinya.

Port Terkait — File Transfer

20 FTP Data 59 Private File Service 69 TFTP 82 XFER Utility 97 Swift-RVF 115 SFTP (Simple FTP) 117 UUCP Path 139 NetBIOS Session

Istilah Terkait

ARP FTP HTTP ICMP IMAP NTP