CVE-2020-21487
CWE-79Published: April 4, 2023· Updated: Jun 17, 2026
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.
Technical Analysis
CVE-2020-21487 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.6.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-21487 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts