CVE-2023-5691 in ChatBot Plugin
Summary
by MITRE • 01/11/2024
The Chatbot for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in version 2.3.9 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
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Analysis
by VulDB Data Team • 06/03/2025
The vulnerability identified as CVE-2023-5691 affects the Chatbot for WordPress plugin version 2.3.9 and represents a critical stored cross-site scripting flaw that specifically targets WordPress multi-site installations. This security weakness stems from inadequate input sanitization and insufficient output escaping mechanisms within the plugin's administrative settings interface. The vulnerability is particularly concerning because it requires only administrator-level privileges or higher to exploit, making it accessible to attackers who have already gained administrative access to a WordPress installation. The flaw manifests when authenticated attackers with appropriate permissions inject malicious scripts through the plugin's settings configuration, which then get stored and executed whenever any user accesses pages containing the injected content.
The technical nature of this vulnerability places it firmly within the CWE-79 category of Cross-Site Scripting, specifically classified as a stored XSS variant where malicious payloads are permanently stored on the server and executed against unsuspecting users. The attack vector is particularly sophisticated because it leverages the plugin's administrative interface, which typically enjoys elevated privileges and trust within the WordPress ecosystem. The vulnerability's impact is amplified in multi-site WordPress installations where the attacker's injected scripts can potentially affect multiple sites within the network. Additionally, the vulnerability requires installations where unfiltered_html has been disabled, which represents a security hardening measure that makes the exploitation more targeted and potentially more damaging.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including session hijacking, credential theft, data exfiltration, and privilege escalation within the compromised WordPress environment. Attackers can craft sophisticated payloads that appear legitimate to administrators and end users, making detection more challenging. The vulnerability's restriction to multi-site installations with disabled unfiltered_html creates a specific attack surface that security teams must monitor carefully, as these configurations often represent enterprise-level WordPress deployments where the potential damage from successful exploitation is significant. The stored nature of the vulnerability means that once exploited, the malicious scripts persist indefinitely until manually removed by administrators.
Mitigation strategies for this vulnerability should prioritize immediate plugin updates to versions that address the input sanitization and output escaping deficiencies. Organizations should implement comprehensive monitoring of administrative settings changes and user activity within WordPress installations, particularly in multi-site configurations. Security teams should consider implementing additional layers of protection including web application firewalls that can detect and block suspicious script injection attempts. The vulnerability highlights the importance of proper input validation and output escaping practices as outlined in the OWASP Top Ten security principles and aligns with ATT&CK technique T1059.001 for command and script injection. Regular security audits of WordPress plugins, especially those with administrative capabilities, should be conducted to identify similar vulnerabilities. Organizations should also consider implementing privileged access management controls and regular security training for administrators to reduce the risk of successful exploitation through social engineering or credential compromise.