CVE-2024-11279 in Schema App Structured Data Plugin
Summary
by MITRE • 12/12/2024
The Schema App Structured Data plugin for WordPress is vulnerable to Reflected Cross-Site Scripting due to the use of add_query_arg without appropriate escaping on the URL in all versions up to, and including, 2.2.4. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/18/2025
The Schema App Structured Data plugin for WordPress presents a critical security vulnerability classified as CVE-2024-11279, which manifests as a reflected cross-site scripting flaw. This vulnerability exists within the plugin's handling of URL parameters and represents a significant risk to WordPress installations that utilize this specific plugin. The issue affects all versions up to and including 2.2.4, indicating a widespread exposure across numerous installations that have not yet been updated to address this security gap.
The technical root cause of this vulnerability lies in the improper use of WordPress's add_query_arg function, which fails to apply adequate escaping mechanisms when processing URL parameters. This function is commonly used to manipulate query strings in WordPress applications, but in this case it does not sufficiently sanitize input data before incorporating it into the URL structure. The lack of proper output escaping creates an environment where malicious payloads can be injected into URL parameters and subsequently executed when the modified URLs are accessed by users. This behavior aligns with CWE-79, which specifically addresses cross-site scripting vulnerabilities due to insufficient output escaping.
The operational impact of this vulnerability extends beyond simple script injection, as it enables unauthenticated attackers to craft malicious URLs that can execute arbitrary JavaScript code in the context of a victim's browser. This means that an attacker could potentially perform actions such as stealing user sessions, redirecting victims to malicious sites, or even modifying the content displayed on legitimate web pages. The vulnerability's exploitation requires social engineering to trick users into clicking on crafted links, but once executed, it can compromise user data and browser sessions. This attack vector falls under the ATT&CK framework's technique T1566, which covers social engineering tactics used to gain initial access to systems.
The reflected nature of this XSS vulnerability means that the malicious script is reflected off the web server rather than being stored on the server itself, making it particularly challenging to detect and prevent. Attackers can craft URLs that contain malicious scripts in parameters, and when a user clicks such a link, the script executes in their browser within the context of the vulnerable plugin's page. This creates a persistent threat that can affect multiple users who encounter the malicious link, especially in environments where users frequently click on links from external sources or where the plugin is widely used across multiple sites. The vulnerability's presence in the URL handling mechanism makes it particularly insidious as it can be exploited through various attack vectors including email links, social media posts, or even within the WordPress admin interface itself.
Organizations using this plugin should immediately implement mitigations to protect their WordPress installations from potential exploitation. The most effective immediate solution involves updating to the latest available version of the Schema App Structured Data plugin where this vulnerability has been addressed. Additionally, administrators should consider implementing content security policies that restrict script execution and monitor their server logs for suspicious URL patterns. Network-level protections such as web application firewalls can also help detect and block malicious requests containing known XSS patterns. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other plugins and themes, as this vulnerability demonstrates the importance of proper input validation and output escaping in WordPress applications. The ATT&CK framework's technique T1190, which covers exploitation of vulnerabilities in web applications, emphasizes the need for comprehensive patch management and security monitoring to prevent successful exploitation of such flaws.