CVE-2020-19201 Explained : Impact and Mitigation

A Stored Cross-Site Scripting (XSS) vulnerability was discovered in the pfSense software WebGUI, affecting Netgate pfSense version 2.4.4-p2 and earlier.

Understanding CVE-2020-19201

This CVE involves a Stored XSS vulnerability in the status_filter_reload.php page of pfSense software WebGUI.

What is CVE-2020-19201?

The vulnerability allowed for stored XSS via the descr (description) parameter on NAT rules.

The Impact of CVE-2020-19201

The vulnerability could be exploited to execute malicious scripts within the context of a user's session, potentially leading to unauthorized actions.

Technical Details of CVE-2020-19201

The technical aspects of the vulnerability are as follows:

Vulnerability Description

The page did not encode output from the filter reload process, enabling the stored XSS attack.

Affected Systems and Versions

Netgate pfSense version 2.4.4-p2 and earlier

Exploitation Mechanism

Exploitation was possible via the descr (description) parameter on NAT rules.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of this vulnerability:

Immediate Steps to Take

Update pfSense software to version 2.4.4-p3 or later.
Monitor for any unusual activities on the affected systems.

Long-Term Security Practices

Regularly review and update security configurations on pfSense installations.
Educate users on safe browsing practices to mitigate XSS risks.

Patching and Updates

Apply patches and updates provided by Netgate to address the vulnerability and enhance system security.