CVE-2023-7071 in Essential Blocks Plugin
Summary
by MITRE • 01/11/2024
The Essential Blocks – Page Builder Gutenberg Blocks, Patterns & Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Table of Contents block in all versions up to, and including, 4.4.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 04/11/2026
The Essential Blocks plugin for WordPress represents a popular collection of gutenberg blocks designed to enhance content creation capabilities for wordpress users. This particular vulnerability affects versions up to and including 4.4.6 where the Table of Contents block implementation contains a critical stored cross-site scripting flaw. The vulnerability stems from inadequate input sanitization and output escaping mechanisms within the plugin's codebase, creating a persistent security weakness that can be exploited by authenticated attackers.
Attackers with contributor-level access or higher can leverage this vulnerability to inject malicious javascript code into pages through the Table of Contents block functionality. The stored nature of this vulnerability means that the injected scripts are permanently saved within the wordpress database and will execute whenever any user accesses the affected pages. This creates a significant risk as the malicious code can persist long after the initial injection and can target unsuspecting visitors who access the compromised content.
The technical flaw manifests in the plugin's failure to properly sanitize user input when processing table of contents data structures. When users create or modify content using the Table of Contents block, the plugin does not adequately validate or escape the input parameters before storing them in the database. This allows attackers to inject malicious javascript payloads that are subsequently executed in the browsers of any user who views the affected pages. The vulnerability affects the core functionality of the plugin's content management system and represents a failure in the principle of least privilege within the wordpress ecosystem.
From an operational perspective, this vulnerability creates a substantial risk for wordpress sites that utilize the Essential Blocks plugin, particularly those with multiple user roles or contributor-level access. The impact extends beyond simple data theft as attackers could potentially redirect users to malicious sites, steal session cookies, or perform other malicious activities through the executed javascript code. The vulnerability is particularly concerning because it requires minimal privileges to exploit, making it accessible to users who typically have limited administrative capabilities within wordpress environments.
The security implications of this vulnerability align with common weakness enumerations such as CWE-79, which specifically addresses cross-site scripting flaws in web applications. This classification emphasizes the importance of proper input validation and output escaping mechanisms. Additionally, the vulnerability maps to several attack techniques within the attack tree framework including credential theft through session hijacking and user redirection attacks. Organizations should consider this vulnerability as part of their broader security posture assessment and implement immediate remediation measures.
Mitigation strategies should include immediate updating of the Essential Blocks plugin to versions that address this vulnerability, implementing additional input validation measures at the wordpress level, and monitoring for any suspicious activity related to the Table of Contents block functionality. Administrators should also consider implementing role-based access controls that limit contributor-level privileges to specific content areas and establish regular security auditing procedures to detect similar vulnerabilities in other plugins. The incident highlights the critical importance of maintaining up-to-date wordpress plugins and the necessity of comprehensive security testing for third-party components within wordpress environments.