Joomla! is one of the world’s most popular content management systems (CMS) used by millions of websites. However, between versions 4.. and 4.2.4, there was a hidden danger lurking inside its media manager component, com_media. This vulnerability, assigned CVE-2022-27914, allowed attackers to inject and execute malicious JavaScript in the context of logged-in users by exploiting weak input filtering—a classic reflected cross-site scripting (XSS) flaw.
Let’s break down how this works, see exactly how an attack looks, and what you need to do to protect yourself.
What is CVE-2022-27914?
This vulnerability affects Joomla! versions 4.. through 4.2.4. In the core Media Manager (com_media), user input wasn’t being filtered or sanitized properly in certain parameters. This gave attackers a way to inject arbitrary JavaScript into the page, which would run when an authenticated user followed a specially crafted link.
Who’s at risk?
Anyone running Joomla! sites within those versions, especially if they allow users to operate or preview media content while logged in as administrators or editors.
How Does the Exploit Work?
Reflected XSS takes advantage of web applications that include user data in their responses without proper escaping. In this case, attackers could send a link with JavaScript in a URL query parameter. When a user with the right permissions clicked it, the script would execute in their browser under their Joomla! session.
Here’s what a malicious URL could look like (for demonstration purposes only)
https://vulnerablesite.com/administrator/index.php?option=com_media&view=media&path=<img src=x onerror=alert('XSS')>
The parameter path is vulnerable.
- <img src=x onerror=alert('XSS')> is a classic XSS payload; when injected, it’ll pop up a JavaScript alert.
Snippet in a phishing email or chat
<a href="https://vulnerablesite.com/administrator/index.php?option=com_media&view=media&path=%3Cimg%20src%3Dx%20onerror%3Dalert('XSS')%3E">;
Check out these new media files!
</a>
If a privileged user clicks, their session could be compromised.
Phishing: Injected scripts could mimic login prompts or steal credentials.
- Defacement/Spam: Attackers could inject fake notifications or redirect users.
Original advisory:
- Joomla! Security Announcements
- NVD Entry
Conclusion
CVE-2022-27914 showed how dangerous even a small XSS flaw in a high-privilege backend component can be. If you maintain a Joomla! site, always keep your installation up to date and educate all users about phishing and suspicious links.
Stay safe, patch often, and always treat user input with suspicion—even if it’s your own!
*If you want more technical deep dives like this, follow our cybersecurity series, and feel free to ask about other CVEs!*
Timeline
Published on: 11/08/2022 19:15:00 UTC
Last modified on: 11/09/2022 13:59:00 UTC