CVE-2024-3903 — The Add Custom CSS and JS WordPress plugin through 1

The Add Custom CSS and JS WordPress plugin through 1.20 does not have CSRF check in some places, and is missing sanitisation as well as escaping, which could allow attackers to make logged in as author and above add Stored XSS payloads via a CSRF attack

01What is this vulnerability?

The Add Custom CSS and JS WordPress plugin through 1.20 does not have CSRF check in some places, and is missing sanitisation as well as escaping, which could allow attackers to make logged in as author and above add Stored XSS payloads via a CSRF attack

02Affected products

Vendor	Product	Versions
Unknown	Add Custom CSS and JS	0

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

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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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: 2024-05-09T06:00:02.924Z
• Last modified: 2024-08-01T20:26:56.964Z

09References

• wpscan.com — https://wpscan.com/vulnerability/0a0e7bd4-948d-47c9-9219-380bda9f3034/