CVE-2024-56245 in Premium Blocks Plugin
Summary
by MITRE • 01/02/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Leap13 Premium Blocks – Gutenberg Blocks for WordPress allows Stored XSS.This issue affects Premium Blocks – Gutenberg Blocks for WordPress: from n/a through 2.1.42.
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Analysis
by VulDB Data Team • 02/16/2025
This vulnerability represents a critical cross-site scripting flaw that specifically targets the Leap13 Premium Blocks plugin for WordPress, a widely used Gutenberg block library. The issue manifests as improper neutralization of input during web page generation, creating an environment where malicious scripts can be persistently stored and executed within the target system. The vulnerability is classified as a stored XSS attack vector, meaning that malicious code injected by an attacker can be permanently saved in the application's database and subsequently executed whenever legitimate users view affected pages. This particular flaw affects all versions of the Premium Blocks plugin from the initial release through version 2.1.42, indicating a prolonged period during which the vulnerability remained unaddressed.
The technical implementation of this vulnerability stems from inadequate sanitization and validation of user-supplied input within the plugin's block generation mechanisms. When administrators or content creators utilize the premium blocks functionality to create or modify web content, the system fails to properly escape or filter potentially malicious input before storing it in the WordPress database. This oversight allows attackers to inject malicious JavaScript code through various input fields within the Gutenberg editor interface, particularly in block configuration parameters that are not adequately sanitized. The vulnerability operates at the application layer and specifically impacts the web page generation process where user input is rendered without proper security controls.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to perform a wide range of malicious activities within the context of the compromised WordPress installation. Successful exploitation could enable attackers to steal session cookies, hijack user accounts, modify content, inject malicious advertisements, or even escalate privileges within the WordPress environment. The stored nature of this XSS vulnerability means that the malicious payload persists even after the initial injection, making it particularly dangerous as it can affect multiple users over extended periods without requiring repeated exploitation attempts. Additionally, the vulnerability affects the entire WordPress ecosystem where the plugin is installed, potentially compromising not just individual sites but entire networks of interconnected installations.
Security mitigations for this vulnerability primarily involve immediate patching of the affected plugin to version 2.1.43 or later, which contains the necessary code fixes to properly sanitize and neutralize user input. System administrators should also implement additional defensive measures including input validation at multiple layers, output encoding for all dynamic content, and regular security audits of installed plugins. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and maps to ATT&CK technique T1566.001 for initial access through malicious content injection. Organizations should also consider implementing web application firewalls and content security policies to provide additional protection layers against similar exploitation attempts. Regular monitoring of plugin repositories and security advisories remains crucial for maintaining protection against future vulnerabilities in the WordPress ecosystem.