CVE-2021-24988 : Security Advisory and Response

WordPress plugin WP RSS Aggregator version before 4.19.3 is affected by a Stored Cross-Site Scripting (XSS) vulnerability that could allow authenticated subscribers to execute malicious scripts.

Understanding CVE-2021-24988

This vulnerability arises from a lack of sanitization and escaping of data in the System Info admin dashboard, enabling attackers to inject arbitrary code.

What is CVE-2021-24988?

The WP RSS Aggregator WordPress plugin version prior to 4.19.3 fails to properly handle data output, potentially leading to Stored XSS due to missing authorization and Cross-Site Request Forgery (CSRF) checks.

The Impact of CVE-2021-24988

An authenticated user, like a subscriber, can exploit this vulnerability to execute arbitrary scripts within the application, posing a significant security risk.

Technical Details of CVE-2021-24988

This section delves into the specifics of the vulnerability.

Vulnerability Description

The issue stems from inadequate data sanitization in the System Info admin dashboard, allowing attackers to insert malicious payloads using the wprss_dismiss_addon_notice AJAX action.

Affected Systems and Versions

WP RSS Aggregator versions earlier than 4.19.3 are vulnerable to this Stored XSS flaw, exposing websites to potential exploitation.

Exploitation Mechanism

By leveraging the lack of authorization and CSRF checks in the plugin, authenticated users such as subscribers can manipulate the addon parameter to execute harmful scripts.

Mitigation and Prevention

To safeguard your system from CVE-2021-24988, consider the following preventive measures.

Immediate Steps to Take

Update WP RSS Aggregator to version 4.19.3 or later to patch the vulnerability.
Regularly monitor and audit user permissions to limit the impact of potential attacks.

Long-Term Security Practices

Implement strict input validation and output encoding practices within your WordPress plugins to prevent XSS vulnerabilities.
Educate users on safe browsing habits and encourage the reporting of suspicious activities.

Patching and Updates

Stay informed about security updates for WP RSS Aggregator and promptly apply patches to fortify your website against known vulnerabilities.