CVE-2025-49667 — Win32k Privilege Escalation Exploit

✔ Tested: Windows 10
✘ Not Working: Windows 11

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🧭 Table of Contents

1. Vulnerability Details
2. Affected Systems
3. Exploit Workflow
4. Compilation Instructions
5. Exploit Output Example
6. Exploit Flow Diagram
7. Notes
8. Disclaimer

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🔥 Vulnerability Details

• CVE ID: CVE-2025-49667 | MITRE
• Type: Double Free (CWE-415)
• Component: Windows Win32 Kernel Subsystem (win32k.sys)
• Impact: Local Privilege Escalation (LPE → SYSTEM)
• CVSS Score: 7.8 (High)
• Attack Vector: Local, low-complexity exploit

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💻 Affected Systems

• ✔ Windows 10 (1909 → 22H2)
• ✘ Windows 11 (patched by default)
• ✘ Windows Server (partially mitigated)

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⚡ Exploit Workflow

1. Trigger vulnerable syscall in win32k.sys.
2. Force a double free on kernel memory object.
3. Reallocate freed memory with controlled data.
4. Overwrite kernel function pointer.
5. Escalate to NT AUTHORITY\SYSTEM.

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🛠 Compilation Instructions

• with Visual Studio Command Prompt:

cl.exe /EHsc /O2 /std:c++17 /DWIN32 /D_WINDOWS /DNDEBUG exploit.cpp /link ntdll.lib winhttp.lib psapi.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /MACHINE:X64 /SUBSYSTEM:CONSOLE

• with MinGW-w64:

g++ -O2 -std=c++17 -m64 -DWIN32 -D_WINDOWS -DNDEBUG -o exploit.exe exploit.cpp -lntdll -lwinhttp -lpsapi -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -luuid -lodbc32 -lodbccp32

• Run with:

exploit.exe

📟 Exploit Output Example

C:\Users\yuri08> whoami
yuri08

C:\Users\yuri08> exploit.exe
[*] Triggering double free...
[*] Overwriting function pointer...
[*] Gaining SYSTEM privileges...
[+] Exploit successful!

C:\Windows\system32> whoami
nt authority\system

📜Exploit Flow Diagram

+-----------------------+
| Userland Process      |
+----------+------------+
           |
           v
+-----------------------+
| Call vulnerable API   |
| (win32k.sys)          |
+----------+------------+
           |
   Double Free Trigger
           |
           v
+-----------------------+
| Kernel Object Freed   |
+----------+------------+
           |
   Fake Object Spray
           |
           v
+-----------------------+
| Overwrite Func Ptr    |
+----------+------------+
           |
   SYSTEM Privileges
           |
           v
+-----------------------+
| NT AUTHORITY\SYSTEM   |
+-----------------------+

📝 Notes

• Requires local access (no remote vector).

• Works reliably on Windows 10 pre-patch.

• May cause BSOD if heap spray fails.

• Debug with WinDbg: !analyze -v

⚠ Disclaimer

• This exploit code and documentation are provided strictly for educational and research purposes only.
• Do not use on systems without explicit authorization.
• You are fully responsible for your actions.

🕶 Stay safe, hack the planet responsibly.