CVE-2024-29047 - Unpacking Microsoft OLE DB Driver for SQL Server Remote Code Execution

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In the fast-moving world of cybersecurity, new vulnerabilities are discovered every week that threaten systems we use every day. One critical issue reported this year is CVE-2024-29047: a remote code execution (RCE) vulnerability in Microsoft’s OLE DB Driver for SQL Server. In this post, I’ll break down the basics, show how it works with simple code, and explain how attackers might use it—so you can better protect your systems.

What is CVE-2024-29047?

CVE-2024-29047 refers to a high-severity RCE vulnerability (CVSS Score: 8.8, High) affecting versions of the Microsoft OLE DB Driver for SQL Server prior to version 19.3..1. The OLE DB driver is a key component for applications to connect and interact with SQL Server databases on Windows.

Official Reference

- Microsoft Security Guide
- NVD – CVE-2024-29047

How Does the Vulnerability Work?

Attackers can exploit this vulnerability by sending specifically crafted requests to an application that uses the vulnerable OLE DB driver. If successful, the attacker can execute code remotely on the server, with the same permissions as the application running the driver.

Why is this a big deal? Because many apps and web services use OLE DB to talk to SQL Server. If the process under attack has admin rights, the attacker could take over the whole server.

Here’s a basic example in C# to show how apps connect to SQL Server using OLE DB

using System.Data.OleDb;

string connStr = "Provider=MSOLEDBSQL;Data Source=YOUR_SQL_SERVER;Initial Catalog=TestDB;User ID=sa;Password=your_password";
using (OleDbConnection conn = new OleDbConnection(connStr))
{
    conn.Open();
    // Vulnerable if unpatched driver is used
    OleDbCommand cmd = new OleDbCommand("SELECT * FROM Users WHERE Name = '" + userInput + "'", conn);
    OleDbDataReader reader = cmd.ExecuteReader();
    // ...
}

An attacker manipulating userInput here (especially with a vulnerable driver and no input validation) could potentially trigger the flawed code in the OLE DB library and execute arbitrary commands on your server.

What does exploit look like?

As of June 2024, there is no public proof-of-concept exploit available for this exact vulnerability. However, the general attack flow would look like this:

Target Application: Attacker identifies an app using the outdated OLE DB SQL Server driver.

2. Craft Payload: They create a payload (malicious string or packet) that exploits the OLE DB parsing bug.
3. Trigger Execution: They send the payload via the application interface (like through a web form, API call, or remote script).
4. Run Code on Server: If successful, attacker’s code runs on the victim server with the privileges of the application.

Important: This is NOT just SQL Injection. Even with parameterized queries, the flaw exists in the OLE DB’s internal code parsing logic.

Sample Attack Layout

USER --> WebApp (uses OLE DB Driver) --> SQL Server

Malicious Input -[Over OLE DB]-> Vulnerable OLE DB SQL Driver --> RCE on the server

How to Fix?

Update Immediately:

Apply the latest OLE DB driver version (19.3..1 or newer). Download from official sources

- Microsoft OLE DB Driver for SQL Server download

Audit Your Applications:

Consider switching to more modern data access technologies (e.g., ADO.NET with SqlClient).

Other Best Practices:

Conclusion

CVE-2024-29047 affects a wide range of businesses running apps connected to SQL Server through OLE DB. Anyone using Microsoft OLE DB drivers must update NOW to prevent possible remote code execution attacks. While no public exploit is circulating (yet), attackers are likely to target unpatched systems soon after disclosure.

Timeline

Published on: 04/09/2024 17:15:58 UTC
Last modified on: 04/10/2024 13:24:00 UTC