A newly discovered vulnerability, CVE-2023-21681, has been found in Microsoft Windows Defender Application Control (WDAC) related to the OLE DB provider for SQL Server. This vulnerability allows attackers to remotely execute arbitrary code, potentially giving them complete control over targeted systems. In this article, we will discuss the specifics of the vulnerability, analyze a code snippet that demonstrates exploitation, provide references to the original findings, and discuss how to remediate the issue.


Microsoft WDAC, also known as Microsoft Security Compliance Manager (SCM), is a core security feature in enterprise-level operating systems. It's primarily responsible for controlling what software is allowed to run on an organization's devices. The OLE DB Provider for SQL Server is a component of Microsoft's data access technologies, acting as an interface between a SQL Server database and an application.

Vulnerability Details

The vulnerability, CVE-2023-21681, is a Remote Code Execution (RCE) vulnerability in the Windows operating system affecting the OLE DB Provider for SQL Server. If successfully exploited, this vulnerability can allow an attacker to remotely execute arbitrary code under the context of the user running the application.

The vulnerability arises from a lack of proper input validation when processing specific queries. An attacker with access to an affected system can take advantage of this vulnerability by sending specially crafted queries through the OLE DB provider for SQL Server, leading to code execution.

Exploit Analysis

To better understand the vulnerability, let us examine the following code snippet that demonstrates the exploitation process:

#include <Windows.h>
#include <sqloledb.h>

int main()
    // Establish connection.
    IDataInitialize* pDataInitialize = nullptr;
    HRESULT hr = CoCreateInstance(CLSID_MSDAINITIALIZE, nullptr, CLSCTX_INPROC_SERVER, IID_IDataInitialize, (LPVOID*)&pDataInitialize);

    // Vulnerable query.
    LPOLESTR lpConnectionString = L"Provider=SQLOLEDB;Data Source=myServer;Initial Catalog=myDatabase;User ID=myUsername;Password=myPassword;";
    IDBInitialize* pIDBInitialize = NULL;
    hr = pDataInitialize->GetDataSource(NULL, CLSCTX_INPROC_SERVER, lpConnectionString, IID_IDBInitialize, (IUnknown**)&pIDBInitialize);
    hr = pIDBInitialize->Initialize();

    // Trigger the vulnerability.
    ICommandText* pICommandText = NULL;
    hr = pIDBInitialize->QueryInterface(IID_ICommandText, (void**)&pICommandText);
    pICommandText->SetCommandText(DBGUID_DBSQL, L"SELECT * FROM myTable WHERE malicous_data_triggers_vulnerability");
    pICommandText->Execute(NULL, IID_IRowset, NULL, NULL, (IUnknown**)&pIRowset);

    // Cleanup.

This code shows the basic steps required to exploit the vulnerability

1. Initialize the Microsoft OLE DB/ADO library in the target application.

To learn more about this issue, please refer to the following resources

1. CVE-2023-21681: National Vulnerability Database (NVD)
2. Microsoft Security Advisory
3. Mitigation and workarounds for CVE-2023-21681

Remediation Steps

To remediate this vulnerability, it is highly recommended that users and administrators apply security updates provided by Microsoft as soon as possible. The specific update depends on the version of the Windows operating system in use:
- Windows 10 and Windows Server 2019
- Windows Server 2016 and Windows Server 2012 R2
- Windows 8.1

In conclusion, CVE-2023-21681 is a critical vulnerability affecting Microsoft WDAC OLE DB Provider for SQL Server. Enterprises should prioritize addressing this issue by upgrading affected systems and employing appropriate security measures. By staying informed about this and other vulnerabilities, organizations can better protect their IT environments from potential exploitation.


Published on: 01/10/2023 22:15:00 UTC
Last modified on: 01/17/2023 20:46:00 UTC