CVE-2023-6000 in Popup Builder Plugin
Summary
by MITRE • 01/01/2024
The Popup Builder WordPress plugin before 4.2.3 does not prevent simple visitors from updating existing popups, and injecting raw JavaScript in them, which could lead to Stored XSS attacks.
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Analysis
by VulDB Data Team • 06/18/2025
The vulnerability identified as CVE-2023-6000 affects the Popup Builder WordPress plugin version 4.2.2 and earlier, representing a critical security flaw that undermines the integrity of web applications relying on this popular plugin. This issue stems from insufficient access controls and input validation mechanisms within the plugin's administrative interface, creating a pathway for unauthenticated attackers to exploit the system's trust model. The vulnerability specifically targets the plugin's ability to manage popup content, where legitimate users should have restricted editing capabilities while unauthorized parties gain elevated privileges through improper authentication checks.
The technical implementation of this vulnerability manifests through a lack of proper user role validation and authorization controls within the plugin's backend processing logic. When users attempt to modify existing popups, the system fails to verify whether the requesting entity possesses the necessary permissions to perform such actions. This absence of access control validation creates a direct vector for privilege escalation, allowing any visitor to the website to manipulate popup content through the exposed administrative endpoints. The flaw is particularly concerning because it operates at the application layer where user inputs are processed without adequate sanitization or validation procedures.
The operational impact of this vulnerability extends beyond simple unauthorized modifications, as it enables attackers to inject malicious JavaScript code directly into popup content that gets stored server-side. This stored cross-site scripting vulnerability allows attackers to execute arbitrary code within the context of any user's browser who encounters the compromised popup, potentially leading to session hijacking, credential theft, or further exploitation of the victim's browser environment. The stored nature of this XSS vulnerability means that once the malicious payload is injected, it persists and affects all users who view the affected popups without requiring repeated exploitation attempts.
Security researchers categorize this vulnerability under CWE-285, which addresses insufficient authorization issues in software systems, and it aligns with ATT&CK technique T1059.007 for JavaScript-based command execution. The vulnerability demonstrates poor input validation practices where raw user input is directly processed without proper sanitization, creating multiple attack vectors for malicious actors. The impact is particularly severe in environments where the plugin is widely used, as a single compromised popup can affect thousands of users across different websites.
Organizations should immediately implement the patch released in version 4.2.3 of the Popup Builder plugin, which addresses the authorization bypass and input sanitization issues. Additional mitigations include implementing web application firewalls to monitor for suspicious requests targeting the plugin's administrative endpoints, conducting thorough security audits of all installed plugins, and establishing proper access control policies. The vulnerability underscores the importance of maintaining up-to-date software components and implementing comprehensive input validation strategies that align with OWASP Top Ten security principles. Regular security assessments should include reviewing plugin permissions and access controls to prevent similar authorization bypass scenarios from occurring in other system components.