CVE-2019-16914 : Exploit Details and Defense Strategies

A security vulnerability related to cross-site scripting (XSS) has been identified in pfSense up to version 2.4.4-p3. The issue specifically impacts the services_captiveportal_mac.php file, where the username and delmac parameters are displayed without undergoing any sanitization process.

Understanding CVE-2019-16914

An XSS issue was discovered in pfSense through version 2.4.4-p3, affecting the services_captiveportal_mac.php file by displaying unsanitized username and delmac parameters.

What is CVE-2019-16914?

This CVE identifies a cross-site scripting vulnerability in pfSense versions up to 2.4.4-p3, allowing attackers to execute malicious scripts in the context of an authenticated user's session.

The Impact of CVE-2019-16914

The vulnerability could be exploited by attackers to inject and execute arbitrary scripts, potentially leading to unauthorized actions, data theft, or further compromise of the affected system.

Technical Details of CVE-2019-16914

The technical aspects of the CVE are as follows:

Vulnerability Description

The issue arises from the lack of sanitization of the username and delmac parameters in the services_captiveportal_mac.php file, enabling XSS attacks.

Affected Systems and Versions

pfSense versions up to 2.4.4-p3

Exploitation Mechanism

Attackers can exploit this vulnerability by injecting malicious scripts through the unsanitized username and delmac parameters, potentially compromising the system.

Mitigation and Prevention

Protecting systems from CVE-2019-16914 involves taking immediate and long-term security measures:

Immediate Steps to Take

Update pfSense to the latest patched version.
Implement input validation and output encoding to prevent XSS attacks.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Regularly audit and review code for security vulnerabilities.
Educate users and administrators about the risks of XSS attacks and safe coding practices.

Patching and Updates

Apply security patches promptly to address known vulnerabilities and enhance system security.