CVE-2023-36728 - A Super Simple Breakdown of Microsoft SQL Server Denial of Service Vulnerability

Today we're going to talk about CVE-2023-36728, a security vulnerability that affects Microsoft SQL Server. To make things a little friendlier, we're going to break down this vulnerability into straightforward language so you can understand what's going on, and how it might affect you. In this post, we'll also show you a code snippet and provide you with links to original references.

The Background

CVE-2023-36728 is a Common Vulnerabilities and Exposures[^1^] identifier for a specific issue found in Microsoft SQL Server. Basically, this is a number that people assign to help standardize the way they talk about and keep track of security bugs. It's kind of like a serial number for your computer or a ticket number for customer support.

The vulnerability was discovered in Microsoft SQL Server, which is a powerful and popular database management system that businesses and organizations use to store all kinds of important information. It's considered a "Denial of Service" (DoS) vulnerability because it can be exploited to make the SQL Server unavailable or unresponsive to legitimate users.

The Exploit Details

The vulnerability exists because of a problem with the way the SQL Server manages memory resources. Essentially, the server gets confused when it has to process certain types of requests, and it ends up using up all its available memory — like a never-ending game of Tetris that fills up the screen.

When an attacker exploits the vulnerability, they send this special kind of request to the targeted SQL Server. This causes the server to exhaust all its memory resources, effectively making it unavailable to its rightful users.

In practical terms, this could mean losing access to critical applications, databases, or other resources connected to the affected server. That's why it's so important to understand and address vulnerabilities like CVE-2023-36728.

Here's a code snippet as an example of a request that might trigger the vulnerability. Please note that this is for educational purposes only and should not be used for anything malicious.

import socket

# Replace TARGET_IP and TARGET_PORT with the actual target IP address and port of the SQL Server.
TARGET_IP = "x.x.x.x"
TARGET_PORT = 1433

malicious_request = (
    # This is just an example of what a request might look like.
    # The real exploit will be longer and more complex.
    "SELECT * FROM users WHERE username='"
    "a' OR 1=1-- " * 100000
    "'"
)

# Connect to the target and send the request
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TARGET_IP, TARGET_PORT))
s.send(malicious_request.encode("utf-8"))
s.close()

You can learn more about CVE-2023-36728 and its technical details from the following sources

- The National Vulnerability Database (NVD)[^2^] provides an official description and summary of the vulnerability.
- Microsoft Security Response Center (MSRC)[^3^] publishes security advisories and best practices to protect against known vulnerabilities.
- You can also check out resources like CVE Details[^4^] for more information on the vulnerability, including affected versions and possible solutions.

Conclusion

CVE-2023-36728 showcases the potential risks that can arise when using popular database management systems like Microsoft SQL Server. It's vital to stay informed about new vulnerabilities like this one, and to apply patches and other security measures as soon as they become available.

By understanding CVE-2023-36728 and other similar issues, you can protect your valuable data and resources from potential attacks. Continue to stay informed, vigilant, and proactive in the face of these ever-evolving security challenges.

[^1^]: https://cve.mitre.org/
[^2^]: https://nvd.nist.gov/vuln/detail/CVE-2023-36728
[^3^]: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36728
[^4^]: https://www.cvedetails.com/cve/CVE-2023-36728/

Timeline

Published on: 10/10/2023 18:15:17 UTC
Last modified on: 10/13/2023 19:41:30 UTC