Microsoft SQL Server is a popular database system used by companies big and small. Recently, a new vulnerability (CVE-2024-37322) was reported, affecting the SQL Server Native Client’s OLE DB Provider. This bug could allow remote code execution—meaning an attacker might run malicious software on your server without your knowledge!

In this post, we will break down what this vulnerability is, how it works (with simple code you can understand), and what you can do to keep your data safe.

2. What Is CVE-2024-37322?

CVE-2024-37322 is a serious security flaw in the “SQL Server Native Client OLE DB Provider” (also known as sqlncli).

Here's what makes it dangerous

- If an attacker can craft a special connection string or send a malicious SQL query, they may be able to take control of your SQL Server through the OLE DB interface.
- They could then install programs, steal or modify data, or create new accounts with full permissions.

This bug is tracked here:
- Microsoft Security Update Guide – CVE-2024-37322

3. How the Exploit Works (With Code Snippet)

The root cause lies in how the OLE DB provider parses input—certain characters and queries are not handled safely. An attacker could send a *crafted connection string* that's interpreted by the server in an unexpected way, allowing code execution.

Below is a conceptual code snippet (for educational purposes only!) showing how this might play out attacking a misconfigured SQL Server:

import pyodbc

# Malicious connection string using the vulnerable provider, e.g., 'sqlncli'
connection_string = (
    "Provider=SQLNCLI11;Server=target.sql.server;Database=master;"
    "User ID=attacker;Password=badpassword;"
    # The magic happens here -- inject exploit in the 'Extended Properties'
    "Extended Properties=\"cmdshell=1;cmd=whoami\""
)

try:
    conn = pyodbc.connect(connection_string, timeout=10)
    cursor = conn.cursor()
    cursor.execute("SELECT 1")  # This would trigger payload if server is vulnerable
    print(cursor.fetchall())
except Exception as e:
    print("Exploit attempt failed or server is patched:", e)

The attacker sneaks in *extra properties* that manipulate the server’s behavior.

- If the server’s OLE DB provider parses this string incorrectly, it may execute the command or load a dangerous DLL, giving the attacker a reverse shell or system-level access.

Exploit Effects

- Run system commands, such as adding admin users, installing software, or exfiltrating sensitive data.

You have not installed the June 2024 Microsoft security updates.

Microsoft SQLNCLI is often found in “legacy” applications or scripts that haven’t been updated for years. Check your connection strings and data access code!

Install the June 2024 Microsoft Update for SQL Server and its client drivers.

- Guidance: Microsoft Security Update Guide – CVE-2024-37322

Disable Unused Features:

- If you do not need OLE DB/SQL Native Client, consider disabling or uninstalling it.

Set up alerting on suspicious login attempts and command execution.

Note: If you must use the Native Client, make sure it is always up to date, and avoid accepting user-supplied properties in connection strings.

6. References

- CVE-2024-37322 — Microsoft Security Update Guide
- Official Microsoft SQL Server Downloads
- Microsoft Guidance: Protect SQL Server from Attacks

Final Thoughts

CVE-2024-37322 is a prime example of why keeping every part of your database stack patched is crucial. Even a seemingly innocent provider library can become the weakest link. Patch ASAP, tighten your network perimeter, and audit your code—your data depends on it!

If you're unsure, consult with your IT team or a security pro.

Timeline

Published on: 07/09/2024 17:15:20 UTC
Last modified on: 09/19/2024 17:36:31 UTC