CVE-2024-1504 in SecuPress Free Plugin
Summary
by MITRE • 04/02/2024
The SecuPress Free — WordPress Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.2.5.1. This is due to missing or incorrect nonce validation on the secupress_blackhole_ban_ip() function. This makes it possible for unauthenticated attackers to block a user's IP via a forged request granted they can trick the user into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 04/14/2026
The SecuPress Free WordPress security plugin presents a critical cross-site request forgery vulnerability that affects all versions up to and including 2251. This vulnerability stems from inadequate nonce validation within the secupress_blackhole_ban_ip() function, creating a significant security weakness in WordPress environments that rely on this plugin for protection. The flaw allows unauthenticated attackers to exploit the system by crafting forged requests that can block legitimate users' IP addresses, fundamentally undermining the plugin's intended security functionality. The vulnerability specifically targets the plugin's IP blacklisting mechanism, which is designed to protect WordPress sites from malicious traffic and automated attacks. When an attacker successfully exploits this CSRF vulnerability, they can force the plugin to execute unauthorized IP blocking operations against targets of their choosing, potentially disrupting legitimate user access or even targeting specific users for denial of service.
The technical implementation of this vulnerability demonstrates a failure in proper input validation and request authentication mechanisms within the WordPress plugin architecture. The missing or incorrect nonce validation represents a fundamental breakdown in the security model that should prevent unauthorized modifications to critical system parameters. Nonce values serve as one-time tokens that verify the authenticity of requests and prevent attackers from executing actions on behalf of authenticated users without their knowledge or consent. The absence of proper nonce verification in the secupress_blackhole_ban_ip() function creates a pathway for attackers to manipulate the plugin's behavior through carefully crafted malicious requests. This type of vulnerability falls under the CWE-352 category, which specifically addresses Cross-Site Request Forgery issues in software applications. The vulnerability's impact is particularly severe because it directly undermines the security posture of WordPress installations by allowing attackers to modify core security parameters without proper authentication.
The operational impact of this vulnerability extends beyond simple disruption to potentially enable more sophisticated attack vectors that could compromise entire WordPress installations. An attacker who successfully exploits this CSRF flaw can effectively manipulate the security controls that the plugin is designed to enforce, creating a situation where legitimate security measures become weapons in the hands of malicious actors. This vulnerability particularly affects WordPress sites that depend on SecuPress for IP-based security controls, as it allows attackers to bypass the normal authentication mechanisms that should protect such critical functions. The attack requires minimal technical expertise to execute, as it only necessitates tricking a user into clicking on a malicious link, making it particularly dangerous in environments where users may not be security-aware. The vulnerability essentially transforms the plugin's protective capabilities into a tool for attackers to compromise the very systems it was designed to secure, creating a paradoxical security risk that undermines the trust users place in the plugin.
Organizations using SecuPress Free plugin versions up to 2251 should immediately implement mitigations to address this vulnerability. The most effective immediate solution involves upgrading to a patched version of the plugin that properly implements nonce validation for the affected function. Administrators should also consider implementing additional network-level protections such as web application firewalls that can detect and block suspicious requests targeting the vulnerable plugin endpoints. Security monitoring should be enhanced to detect unusual patterns of IP blacklisting activity that might indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1566.001 highlights its potential for initial access and privilege escalation, as attackers can use the compromised plugin to gain unauthorized control over security functions. Organizations should also review their user access controls and ensure that only authorized personnel can perform IP blacklisting operations, implementing additional layers of authentication where possible. The incident underscores the critical importance of maintaining up-to-date security software and the necessity of implementing comprehensive security monitoring to detect exploitation attempts before they can cause significant damage. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other plugins and system components that may present similar CSRF risks.