## https://sploitus.com/exploit?id=1994C25F-7EC9-5173-B572-042AF6615038
# CVE-2023-21817 - Windows Kerberos LPE Vulnerability Checker
A minimalist C++ Proof of Concept (PoC) / Vulnerability Checker for **CVE-2023-21817**. This utility helps security researchers and system administrators determine whether a Windows system is vulnerable to the Kerberos Local Privilege Escalation (LPE) flaw by interacting with the Local Security Authority (LSA) subsystem.
## Overview
CVE-2023-21817 is a Local Privilege Escalation vulnerability in the Windows Kerberos component. It allows a low-privileged user to bypass security restrictions during a workstation unlock sequence.
This tool attempts to trigger the specific parsing logic via `LsaLogonUser` using the restricted `KerbUnlockLogon` info class. It analyzes the returned `NTSTATUS` code to determine if the security patch is missing.
## Status Code Reference
The tool evaluates the vulnerability status based on the `NTSTATUS` response from the LSA subsystem:
| NTSTATUS Code | Status Name | Verdict | Description |
|---|---|---|---|
| `0xC0000003` | `STATUS_INVALID_INFO_CLASS` | **PATCHED (Secure)** | The patch is active. LSA safely rejected the restricted `KerbUnlockLogon` class in this context. |
| `0xC000006D` | `STATUS_LOGON_FAILURE` | **VULNERABLE (Unpatched)** | The vulnerable handler processed the request and dropped it only because of the dummy credentials. |
| `0xC0000022` | `STATUS_ACCESS_DENIED` | **VULNERABLE (Unpatched)** | The structure bypassed initial checks but failed due to low process privileges. |
| `0xC000005E` | `STATUS_NO_LOGON_SERVERS` | **VULNERABLE (Unpatched)** | The vulnerable handler is active but could not reach a Domain Controller. |
## Requirements
- **Compiler:** Microsoft Visual C++ Compiler (MSVC)
- **IDE:** Visual Studio 2019 / 2022 or MSBuild
- **Windows SDK:** 10.0 or higher
- **Library Dependencies:** `Secur32.lib` (linked automatically via pragma)
## Compilation & Usage
1. Open the project in Visual Studio.
2. Set the build configuration to **Release** and select your target architecture (**x64** or **x86**).
3. Build the solution.
4. Run the compiled executable from the command line:
```cmd
CVE-2023-21817-Checker.exe
```
## Disclaimer
This tool is developed strictly for authorized security testing, educational purposes, and vulnerability research. Do not run it on production systems without proper authorization. The author accepts no responsibility for any misuse or damage caused by this software.