Post Office Protocol (POP) is described as a protocol within the realm of computer networking and the Internet, which is utilized for the extraction and retrieval of email from a remote mail server, making it accessible on the local device. Positioned within the application layer of the OSI model, this protocol enables users to fetch and receive email. The operation of POP clients typically involves establishing a connection to the mail server, downloading all messages, storing these messages locally on the client system, and subsequently removing them from the server. Although there are three iterations of this protocol, POP3 stands out as the most prevalently employed version.
root@kali:~# telnet $ip 110
+OK beta POP3 server (JAMES POP3 Server 2.3.2) ready
USER billydean
+OK
PASS password
+OK Welcome billydean
list
+OK 2 1807
1 786
2 1021
retr 1
+OK Message follows
From: jamesbrown@motown.com
Dear Billy Dean,
Here is your login for remote desktop ... try not to forget it this time!
username: billydean
password: PA$$W0RD!Z
Logging Passwords
POP servers with the setting auth_debug enabled will be increasing the logs generated. However, if auth_debug_passwords or auth_verbose_passwords are set as true, password could be also logged in clear text in those logs.
HackTricks Automatic Commands
Protocol_Name: POP #Protocol Abbreviation if there is one.
Port_Number: 110 #Comma separated if there is more than one.
Protocol_Description: Post Office Protocol #Protocol Abbreviation Spelled out
Entry_1:
Name: Notes
Description: Notes for POP
Note: |
Post Office Protocol (POP) is described as a protocol within the realm of computer networking and the Internet, which is utilized for the extraction and retrieval of email from a remote mail server**, making it accessible on the local device. Positioned within the application layer of the OSI model, this protocol enables users to fetch and receive email. The operation of POP clients typically involves establishing a connection to the mail server, downloading all messages, storing these messages locally on the client system, and subsequently removing them from the server. Although there are three iterations of this protocol, POP3 stands out as the most prevalently employed version.
https://book.hacktricks.xyz/network-services-pentesting/pentesting-pop
Entry_2:
Name: Banner Grab
Description: Banner Grab 110
Command: nc -nv {IP} 110
Entry_3:
Name: Banner Grab 995
Description: Grab Banner Secure
Command: openssl s_client -connect {IP}:995 -crlf -quiet
Entry_4:
Name: Nmap
Description: Scan for POP info
Command: nmap --script "pop3-capabilities or pop3-ntlm-info" -sV -p 110 {IP}
Entry_5:
Name: Hydra Brute Force
Description: Need User
Command: hydra -l {Username} -P {Big_Passwordlist} -f {IP} pop3 -V
Entry_6:
Name: consolesless mfs enumeration
Description: POP3 enumeration without the need to run msfconsole
Note: sourced from https://github.com/carlospolop/legion
Command: msfconsole -q -x 'use auxiliary/scanner/pop3/pop3_version; set RHOSTS {IP}; set RPORT 110; run; exit'
