CVE-2011-10033 in is-human Plugin
Summary
by MITRE • 10/15/2025
The WordPress plugin is-human <= v1.4.2 contains an eval injection vulnerability in /is-human/engine.php that can be triggered via the 'type' parameter when the 'action' parameter is set to 'log-reset'. The root cause is unsafe use of eval() on user-controlled input, which can lead to execution of attacker-supplied PHP and OS commands. This may result in arbitrary code execution as the webserver user, site compromise, or data exfiltration. The is-human plugin was made defunct in June 2008 and is no longer available for download. This vulnerability was exploited in the wild in March 2012.
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Analysis
by VulDB Data Team • 10/16/2025
The vulnerability identified as CVE-2011-10033 represents a critical code injection flaw within the WordPress is-human plugin version 1.4.2 and earlier. This vulnerability exists in the plugin's engine.php file where the application employs the eval() function without proper input sanitization. The attack vector is specifically triggered through manipulation of the 'type' parameter when the 'action' parameter is set to 'log-reset', creating a dangerous condition where user-supplied data directly influences PHP code execution. The exploitation mechanism leverages the fundamental insecurity of eval() usage, which processes arbitrary PHP code provided as a string, making it a prime target for malicious actors seeking to execute unauthorized commands on vulnerable systems. This vulnerability falls under CWE-94, which classifies improper use of eval() as a code injection weakness, and aligns with ATT&CK technique T1059.007 for execution through PHP.
The technical implementation of this vulnerability demonstrates how unsafe parameter handling can lead to complete system compromise. When an attacker crafts a malicious payload for the 'type' parameter, the eval() function processes this input directly without any validation or sanitization measures, allowing arbitrary PHP code execution. This creates a pathway for attackers to execute commands as the webserver user, potentially gaining full control over the compromised WordPress installation. The impact extends beyond simple code execution, as attackers can leverage this vulnerability to perform data exfiltration, deploy backdoors, or establish persistent access to the compromised system. The vulnerability's exploitation in the wild during March 2012 demonstrates its practical threat level and the real-world consequences of such insecure coding practices.
The operational impact of CVE-2011-10033 is severe and multifaceted, encompassing complete site compromise, data loss, and potential lateral movement within network environments. Systems running vulnerable versions of the is-human plugin become immediately susceptible to remote code execution, allowing attackers to install malware, steal sensitive information, or modify website content. The fact that this plugin was discontinued in June 2008 makes it particularly dangerous as administrators may not be actively monitoring for outdated plugins, and the vulnerability has remained unpatched in legacy systems. The exploitation timeline indicates that this vulnerability was actively targeted by threat actors, suggesting that many systems were likely compromised during the period when the vulnerability was known but unaddressed. Organizations with outdated WordPress installations running this plugin would face significant risk of unauthorized access and potential data breaches.
Mitigation strategies for CVE-2011-10033 must prioritize immediate remediation through plugin removal or complete system updates. The most effective approach involves completely uninstalling the is-human plugin from affected WordPress installations, as no patches exist for this vulnerability due to the plugin's discontinuation. System administrators should conduct comprehensive audits to identify all instances of this plugin across their WordPress environments and ensure proper removal procedures are followed. Additionally, implementing robust input validation and sanitization practices throughout WordPress installations can prevent similar vulnerabilities from occurring in other custom code or plugins. Security monitoring should include regular checks for deprecated or abandoned plugins, as these often represent significant attack surfaces. Organizations should also consider implementing web application firewalls and security headers to detect and prevent exploitation attempts, while maintaining up-to-date security practices including regular WordPress core and plugin updates to prevent future vulnerabilities from being exploited.