CVE-2023-3996 in ARMember Lite Membership Plugin
Summary
by MITRE • 10/25/2023
The ARMember Lite - Membership Plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in versions up to, and including, 4.0.16 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 • 04/10/2026
The ARMember Lite membership plugin for WordPress presents a significant security vulnerability classified as CVE-2023-3996, which represents a stored cross-site scripting flaw that can be exploited by authenticated administrators. This vulnerability specifically affects versions up to and including 4.0.16 of the plugin, creating a persistent threat vector that allows attackers with administrative privileges to inject malicious scripts into the WordPress administration interface. The flaw stems from inadequate input sanitization mechanisms and insufficient output escaping practices within the plugin's admin settings implementation, creating an environment where malicious code can be permanently stored and subsequently executed whenever affected pages are accessed by other users.
The technical nature of this vulnerability places it squarely within the CWE-79 category of Cross-Site Scripting, specifically manifesting as a stored XSS variant that operates through the WordPress admin settings interface. Attackers with administrator-level permissions can leverage this weakness to inject malicious scripts that will execute in the context of other users' browsers when they access pages containing the injected content. The vulnerability's impact is particularly concerning because it requires only administrative access rather than elevated privileges, making it accessible to attackers who have already compromised administrator accounts or who have been granted administrative roles through other means. The exploitation mechanism operates through the plugin's handling of user input in administrative settings, where the lack of proper sanitization allows attackers to inject malicious payloads that persist in the database.
This vulnerability's operational impact extends beyond simple script execution to potentially enable more sophisticated attack vectors including session hijacking, credential theft, and privilege escalation within the WordPress environment. The stored nature of the vulnerability means that once injected, malicious scripts will execute automatically whenever affected pages are loaded, creating a persistent threat that can affect any user who accesses those pages. The restriction to multi-site installations and environments where unfiltered_html has been disabled suggests that the vulnerability's exploitation is somewhat constrained by WordPress configuration, but this does not eliminate the risk since administrators can potentially modify these settings or the vulnerability may be present in configurations where such restrictions are bypassed. The attack surface is further expanded by the fact that administrators often have broad access to sensitive system information and user data, making successful exploitation potentially devastating.
The security implications of CVE-2023-3996 align with ATT&CK tactics involving code injection and privilege escalation, as the vulnerability allows attackers to execute arbitrary code within the context of the target system. This type of vulnerability is particularly dangerous in multi-site WordPress installations where administrators may have varying levels of access and where the attack could potentially propagate across multiple sites within the same network. The vulnerability's presence in the plugin's admin settings interface means that attackers can potentially manipulate core WordPress functionality, potentially leading to complete system compromise. Organizations should consider this vulnerability as part of a broader attack surface assessment, particularly in environments where WordPress administrators have elevated privileges and where the plugin is actively used in production environments.
Mitigation strategies should focus on immediate plugin updates to versions that address the XSS vulnerability, along with comprehensive security audits of administrative accounts and access controls. The implementation of proper input validation and output escaping mechanisms within the plugin's codebase represents the fundamental fix required to prevent this class of vulnerability from reoccurring. Organizations should also consider implementing additional security measures such as web application firewalls, regular security monitoring, and access control reviews to prevent unauthorized administrative access. The vulnerability's classification as a stored XSS issue also emphasizes the importance of regular security testing and code reviews to identify similar weaknesses in other plugins and themes that may be present in the WordPress ecosystem. Security teams should prioritize patching this vulnerability as a high-priority item given the administrative access requirements and the potential for persistent exploitation within affected installations.