CVE-2023-5654 — The React Developer Tools extension registers a message listener with window

The React Developer Tools extension registers a message listener with window.addEventListener('message', <listener>) in a content script that is accessible to any webpage that is active in the browser. Within the listener is code that requests a URL derived from t

01What is this vulnerability?

The React Developer Tools extension registers a message listener with window.addEventListener('message', <listener>) in a content script that is accessible to any webpage that is active in the browser. Within the listener is code that requests a URL derived from the received message via fetch(). The URL is not validated or sanitised before it is fetched, thus allowing a malicious web page to…

02Affected products

Vendor	Product	Versions
Meta	React Developer Tools Extension	< 4.28.4

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-10-19T14:28:23.769Z
• Last modified: 2024-09-12T14:35:37.964Z

09References

• gist.github.com — https://gist.github.com/CalumHutton/1fb89b64409570a43f89d1fd3274b231