CVE-2024-0899 in s2Member Plugin
Summary
by MITRE • 04/09/2024
The s2Member – Best Membership Plugin for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions plugin for WordPress is vulnerable to Information Exposure in all versions up to, and including, 230815 via the API. This makes it possible for unauthenticated attackers to see the contents of those posts and pages.
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Analysis
by VulDB Data Team • 04/14/2026
The s2Member WordPress plugin represents a comprehensive membership solution designed to manage various types of memberships, content restriction paywalls, and member access subscriptions for WordPress websites. This plugin has been identified as vulnerable to information exposure through its API interface, affecting all versions up to and including 230815. The vulnerability stems from inadequate access controls within the plugin's API endpoints, which fail to properly authenticate or authorize requests before exposing protected content. This represents a critical security flaw that undermines the fundamental security model of the plugin and the WordPress platform it operates on.
The technical flaw manifests in the plugin's API implementation where specific endpoints fail to validate whether incoming requests originate from authenticated users or possess proper authorization credentials. This weakness allows unauthenticated attackers to directly access and retrieve the contents of protected posts and pages through the API interface. The vulnerability operates at the application layer and specifically targets the plugin's content access controls, making it particularly dangerous as it bypasses the standard WordPress authentication mechanisms that typically protect content. The flaw essentially creates a backdoor through which any user, regardless of their authentication status, can obtain sensitive information that should normally be restricted to authorized members only.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the security posture of WordPress sites utilizing the affected plugin. Attackers can systematically harvest protected content, potentially including premium articles, member-only resources, subscription content, and other sensitive materials that the site owner intended to restrict. This exposure can lead to significant financial losses for subscription-based services, intellectual property theft, and damage to reputation. The vulnerability affects not only the immediate content but also potentially exposes user data and membership information that may be linked to the restricted content, creating cascading security implications for the entire membership ecosystem.
Organizations should immediately implement mitigations including updating to the latest version of the s2Member plugin where the vulnerability has been addressed, implementing additional network-level controls such as rate limiting and access restrictions on API endpoints, and conducting thorough audits of all membership-related plugins. Security teams should also consider implementing web application firewalls to monitor and block suspicious API access patterns and ensure proper authentication enforcement. The vulnerability aligns with CWE-200 (Information Exposure) and may relate to ATT&CK techniques such as T1566 (Phishing) and T1071.004 (Application Layer Protocol: DNS) when attackers leverage the exposed information for further attacks. Additionally, organizations should review their overall security posture and implement proper principle of least privilege controls to minimize the impact of similar vulnerabilities in other plugins or components of their WordPress ecosystem.