CVE-2021-24828 : Security Advisory and Response

The Mortgage Calculator / Loan Calculator WordPress plugin before version 1.5.17 is impacted by a stored Cross-Site Scripting vulnerability that could be exploited by users with a contributor role.

Understanding CVE-2021-24828

This CVE identifies a security issue in the Mortgage Calculator / Loan Calculator WordPress plugin version 1.5.17 and below, allowing contributors to perform Cross-Site Scripting attacks.

What is CVE-2021-24828?

The vulnerability in the Mortgage Calculator / Loan Calculator WordPress plugin before 1.5.17 enables users with a contributor role to execute malicious Cross-Site Scripting attacks, compromising the security of the plugin and potentially the entire site.

The Impact of CVE-2021-24828

The impact of this CVE is significant as it exposes websites using the vulnerable versions of the plugin to Cross-Site Scripting attacks by low-privileged users, leading to potential data theft, defacement, or unauthorized actions on the site. The lack of proper sanitization of attributes in the mlcalc shortcode poses a security risk.

Technical Details of CVE-2021-24828

The technical details of CVE-2021-24828 include:

Vulnerability Description

The vulnerability arises from the plugin's failure to properly escape certain attributes of the mlcalc shortcode, allowing contributors to inject malicious scripts.

Affected Systems and Versions

The affected system includes the Mortgage Calculator / Loan Calculator WordPress plugin versions before 1.5.17.

Exploitation Mechanism

Attackers with a contributor role can exploit the vulnerability by injecting malicious scripts through the mlcalc shortcode, potentially executing unauthorized actions on the target site.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-24828, consider the following steps:

Immediate Steps to Take

Update the Mortgage Calculator / Loan Calculator plugin to version 1.5.17 or newer to eliminate the vulnerability.
Restrict contributor privileges to minimize the impact of Cross-Site Scripting attacks.

Long-Term Security Practices

Regularly update plugins and themes to patch known vulnerabilities.
Implement Content Security Policy (CSP) headers to mitigate Cross-Site Scripting risks.

Patching and Updates

Stay informed about security patches released by plugin developers and apply them promptly to ensure the continued security of your WordPress site.