**우편 프로토콜 (POP)**은 컴퓨터 네트워킹 및 인터넷 영역 내의 프로토콜로 설명되며, 원격 메일 서버에서 이메일을 추출하고 검색하는 데 사용되어 로컬 장치에서 접근할 수 있게 합니다. OSI 모델의 응용 계층에 위치한 이 프로토콜은 사용자가 이메일을 가져오고 수신할 수 있도록 합니다. POP 클라이언트의 작동은 일반적으로 메일 서버에 연결을 설정하고, 모든 메시지를 다운로드하며, 이러한 메시지를 클라이언트 시스템에 로컬로 저장한 후 서버에서 제거하는 과정을 포함합니다. 이 프로토콜에는 세 가지 버전이 있지만, POP3가 가장 널리 사용되는 버전으로 두드러집니다.
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
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'