CVE-2019-16973 : Security Advisory and Response

FusionPBX version prior to 4.5.7, specifically the file contact_edit.php in the app\contacts\ directory, is vulnerable to a Cross-Site Scripting (XSS) attack due to unsanitized input from the URL.

Understanding CVE-2019-16973

This CVE identifies a security vulnerability in FusionPBX versions up to 4.5.7 that can be exploited through the contact_edit.php file.

What is CVE-2019-16973?

The vulnerability in FusionPBX arises from the use of an unsanitized "query_string" variable derived from the URL, which is then reflected in HTML, creating an XSS vulnerability.

The Impact of CVE-2019-16973

The XSS vulnerability in FusionPBX could allow attackers to execute malicious scripts in the context of a user's browser, potentially leading to unauthorized access or data theft.

Technical Details of CVE-2019-16973

FusionPBX's vulnerability to XSS due to unsanitized input from the URL.

Vulnerability Description

The file contact_edit.php in FusionPBX versions prior to 4.5.7 allows unsanitized input from the URL, leading to a Cross-Site Scripting (XSS) vulnerability.

Affected Systems and Versions

FusionPBX versions up to 4.5.7

Exploitation Mechanism

Attackers can inject malicious scripts through the unsanitized "query_string" variable in the URL, which is then reflected in HTML, enabling XSS attacks.

Mitigation and Prevention

Steps to address and prevent the CVE-2019-16973 vulnerability.

Immediate Steps to Take

Update FusionPBX to version 4.5.7 or later to mitigate the XSS vulnerability.
Implement input validation and sanitization to prevent unsanitized data from being reflected in HTML.

Long-Term Security Practices

Regularly monitor and audit web application code for security vulnerabilities.
Educate developers on secure coding practices to prevent XSS and other injection attacks.

Patching and Updates

Apply security patches and updates provided by FusionPBX promptly to address known vulnerabilities.