CVE-2019-20041 Explained : Impact and Mitigation

WordPress before 5.3.1 is vulnerable to a specific issue that allows attackers to bypass input sanitization measures.

Understanding CVE-2019-20041

This CVE identifies a vulnerability in the wp_kses_bad_protocol function within WordPress versions prior to 5.3.1.

What is CVE-2019-20041?

The wp_kses_bad_protocol function in WordPress fails to handle the HTML5 entity with a colon name correctly, enabling malicious actors to evade input sanitization measures.

The Impact of CVE-2019-20041

This vulnerability allows attackers to bypass input sanitization, as demonstrated by the javascript: substring.

Technical Details of CVE-2019-20041

WordPress before version 5.3.1 is affected by this vulnerability.

Vulnerability Description

The wp_kses_bad_protocol function mishandles the HTML5 colon named entity, leading to input sanitization bypass.

Affected Systems and Versions

Product: WordPress
Vendor: WordPress
Versions affected: All versions prior to 5.3.1

Exploitation Mechanism

Attackers can exploit this vulnerability by using the javascript: substring to bypass input sanitization.

Mitigation and Prevention

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

Immediate Steps to Take

Update WordPress to version 5.3.1 or later to mitigate the vulnerability.
Monitor for any suspicious activities on the website.

Long-Term Security Practices

Regularly update WordPress and all plugins to the latest versions.
Implement web application firewalls and security plugins to enhance website security.
Educate users on safe browsing practices to prevent potential attacks.

Patching and Updates

Apply security patches promptly as soon as they are released by WordPress.