Earlier in 2022, a critical security issue was reported in the open-source API gateway management tool, eolinker apinto-dashboard. Having the identifier CVE-2022-3803, this vulnerability exposes the application and its users to Cross-Site Scripting (XSS) attacks through the endpoint /api/discoveries/. In this post, we'll break down what this means, show you a practical exploit, and give resources for further reading.

What is eolinker apinto-dashboard?

eolinker apinto-dashboard is a user-friendly, open-source tool designed to help developers manage APIs with ease. It’s popular due to its slick UI and comprehensive features. But like many systems involving direct user input or output, vulnerabilities can creep in.

The Vulnerability: Quick Overview

- Vulnerability ID: CVE-2022-3803 (VDB-212639)
- Component: /api/discoveries/ endpoint

What is Cross-Site Scripting (XSS)?

XSS is when an attacker injects malicious JavaScript into a web application. If the app reflects this code back in a response, unsuspecting users may execute those scripts in their browser, allowing the attacker to steal sensitive data, cookies, or even hijack the session.

Where’s the Problem?

The endpoint /api/discoveries/ in the vulnerable eolinker apinto-dashboard does not properly sanitize user-supplied input. This means specially-crafted payloads in API requests can end up being rendered as executable code in the browser—classic XSS.

Proof-of-Concept Exploit (Simple Example)

Here's how a malicious actor might exploit this vulnerability. Suppose the front-end displays data from /api/discoveries/ and simply trusts whatever comes back.

Malicious Request (using curl)

curl -X POST http://<TARGET_HOST>/api/discoveries/ \
  -H 'Content-Type: application/json' \
  -d '{"search":"<img src=x onerror=alert(1)>" }'

The JavaScript payload <img src=x onerror=alert(1)> is sent as part of the request.

- The dashboard processes and reflects this input directly into its response or subsequent rendered content.
- Any user viewing this data will see an alert pop up—in a real attack, the script could steal cookies or run code in the user's session.

Why is This Bad?

If an attacker gets a logged-in admin or user to visit a page or API output containing the payload, the attacker gains the ability to:

Is There a Patch?

The eolinker team may release an update—make sure to review official announcements and always apply the latest patches.

Mitigation Tip:  
Until an official patch is available, filter or escape user input and output at all entry/exit points. Using a web application firewall (WAF) can also help block known payloads.

References

- VulDB CVE-2022-3803 Entry
- NVD Details
- Eolinker apinto-dashboard GitHub
- What is XSS? (OWASP)

Conclusion

CVE-2022-3803 in eolinker apinto-dashboard is a proven, public XSS vulnerability. Attackers can exploit /api/discoveries/ remotely, leading to severe consequences for users and admins. As with all XSS bugs, the takeaway is *never trust or directly output user input.*

Stay safe:

Timeline

Published on: 11/01/2022 16:15:00 UTC
Last modified on: 11/02/2022 15:10:00 UTC