CVE-2021-27933 : Security Advisory and Response

pfSense 2.5.0 allows XSS via the services_wol_edit.php Description field.

Understanding CVE-2021-27933

This CVE involves a cross-site scripting (XSS) vulnerability in pfSense 2.5.0, specifically through the Description field in services_wol_edit.php.

What is CVE-2021-27933?

CVE-2021-27933 is a security vulnerability that enables attackers to execute malicious scripts on the victim's web browser through the Description field in services_wol_edit.php in pfSense 2.5.0, potentially leading to unauthorized actions.

The Impact of CVE-2021-27933

Exploitation of this vulnerability could result in potential XSS attacks, compromising the security and integrity of the affected pfSense system. Attackers could trick users into executing unintended actions or disclosing sensitive information.

Technical Details of CVE-2021-27933

This section provides an overview of the vulnerability's technical aspects.

Vulnerability Description

The vulnerability allows an attacker to inject and execute malicious scripts through the Description field in services_wol_edit.php of pfSense 2.5.0, leading to XSS attacks.

Affected Systems and Versions

pfSense 2.5.0 is confirmed to be affected by this vulnerability. Other versions may also be at risk if they utilize the same codebase.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting and submitting malicious scripts through the vulnerable Description field. When a user views the specific content, the script executes in their browser.

Mitigation and Prevention

To safeguard your systems from CVE-2021-27933, it is crucial to implement appropriate mitigation strategies and security practices.

Immediate Steps to Take

Users are advised to update pfSense to a patched version that addresses the XSS vulnerability. Additionally, avoid interacting with untrusted or suspicious links that could potentially trigger the exploit.

Long-Term Security Practices

Regularly monitor security advisories and promptly apply security updates to mitigate future vulnerabilities. Educate users on recognizing and avoiding phishing attempts that might exploit XSS vulnerabilities.

Patching and Updates

Stay informed about security patches released by pfSense and ensure timely installation to protect your systems from known vulnerabilities.