CVE-2021-24934 Scanner

Visual CSS Style Editor is a plugin primarily used by web developers and WordPress site administrators for customizing website styles without coding. It provides an easy-to-use interface for changing CSS properties of web elements, allowing for a more visually-oriented approach to web design. Users of this product are generally non-technical and look for efficient customization of their site appearance within the WordPress environment. Popular among bloggers, business websites, and small online store owners, the tool intends to simplify style adjustments significantly. Its wide usage in WordPress platforms reflects the growing demand for versatile, easy-to-navigate customization plugins. Built by YellowPencil, the plugin garners attention for helping users achieve professional styling results effortlessly.

The Cross-Site Scripting (XSS) vulnerability reported affects the Visual CSS Style Editor and allows execution of JavaScript-related attacks. It surfaces when the 'wyp_page_type' parameter is not properly sanitized before rendering in an admin page. Attackers leverage this to insert malicious scripts into webpages that execute in the victim’s browser when accessed. Such scripts can result in sensitive data exposure or unauthorized manipulation of webpage content. This is particularly concerning given the wide adoption of the plugin by non-technical users who may not recognize malicious activity arising from these scripts. Reflected XSS targets administrative pages, exploiting overlooked entry points due to improper input handling.

Technical discovery of this XSS issue hinges on the 'wyp_page_type' parameter not undergoing proper sanitation and escaping processes in administrative views. When the plugin outputs this parameter's content, it does so inadequately, allowing payload injection. Vulnerable endpoints include the admin.php page with specific query parameters leading to script inclusion. This oversight in input validation and output handling leads to potential points of entry for attackers to inject and execute scripted payloads. The crafted payloads, when accessed, trigger within the user’s browser, executing the injected script. Mitigation revolves around tightening input validation and output protocols to prevent such executions from occurring unnoticed.

If exploited, this vulnerability could result in various effects; attackers could perform phishing attacks by mimicking legitimate site elements, thereby stealing sensitive information such as credentials. Additionally, users with injected scripts could unwittingly execute actions on their accounts or administrative backends, causing data integrity issues or unauthorized access. A successful attack might also tarnish the site’s reputation, impacting user trust and incoming traffic. Administrators could face nuanced ways of redirection or manipulated content, impacting overall site security without clear evidence of fault. The exploration of weaknesses through XSS could lead to data breaches or loss of user data integrity.

REFERENCES

• https://wpscan.com/vulnerability/0aa5a8d5-e736-4cd3-abfd-8e0a356bb6ef/
• https://nvd.nist.gov/vuln/detail/CVE-2021-24934