POP3

Source CTF and HTB Academy

• Usually ports 110, 995

POP3 provides listing, retrieving, and deleting emails as functions at the email server.

Commands

Command	Description
USER username	Identifies the user.
PASS password	Authentication of the user using its password.
STAT	Requests the number of saved emails from the server.
LIST	Requests from the server the number and size of all emails.
RETR id	Requests the server to deliver the requested email by ID.
DELE id	Requests the server to delete the requested email by ID.
CAPA	Requests the server to display the server capabilities.
RSET	Requests the server to reset the transmitted information.
QUIT	Closes the connection with the POP3 server.

Dangerous settings

Same as imap see here

Enumeration

• openssl s_client -connect TARGET-IP:995 -crlf -quiet (995 is the port)

• sudo nmap 10.129.14.128 -sV -p110,995 -sC

• sudo nmap -p 110,995 --script=pop3-* TARGET-IP will try different enumeration including username enumeration

• openssl s_client -connect 10.129.14.128:pop3s

• curl -k 'pop3s://10.129.250.84' --user robin:robin -v

Password spray & bruteforce

• hydra pop3://TARGET-IP/TLS -L users.txt -P passwords.txt

Connect to an email account with openssl

openssl s_client -connect TARGET-IP:995
USER [e-mail]
PASS password

Resources

110,995 - Pentesting POPHackTricks

Pentesting POP - Hacktricks