CVE-2020-21487 Cross-site scripting in n/a

Critical 9.6 Published 4 Apr 2023 Updated 13 Feb 2025

Attackers can execute arbitrary code via Cross-Site Scripting in the ACME package's certificate configuration field, compromising pfSense network devices.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2020-21487?

CVE-2020-21487 is a critical cross-site scripting vulnerability in n/a, published on 4 Apr 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Cross Site Scripting vulnerability found in Netgate pfSense 2.4.4 and ACME package v.0.6.3 allows attackers to execute arbitrary code via the RootFolder field of acme_certificates.php.

Weakness: CWE-79

Which versions are affected by CVE-2020-21487?

It affects 2 products.

Products include Netgate Pfsense, Netgate Pfsense Acme Package.

How do I fix CVE-2020-21487?

No fix has been published for CVE-2020-21487 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2020-21487 being exploited?

There is no known exploitation of CVE-2020-21487 in the wild and no public exploit code.

Sources

Also known as GHSA-rff5-9cw2-46c6.