CVE-2011-3853 in Hybrid
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Hybrid theme before 0.10 for WordPress allows remote attackers to inject arbitrary web script or HTML via the cpage parameter.
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Analysis
by VulDB Data Team • 02/11/2019
The CVE-2011-3853 vulnerability represents a classic cross-site scripting flaw affecting the Hybrid theme for WordPress prior to version 0.10. This vulnerability resides in the theme's handling of user-supplied input through the cpage parameter, creating an exploitable entry point for malicious actors to execute arbitrary web scripts or HTML code within the context of affected websites. The Hybrid theme, which was widely used among WordPress installations, became susceptible to this attack vector due to insufficient input validation and output sanitization mechanisms.
The technical implementation of this vulnerability stems from the theme's failure to properly sanitize or escape the cpage parameter before incorporating it into dynamic web page content. When a user or attacker supplies malicious input through this parameter, the theme processes it without adequate security controls, allowing the injected code to execute in the browsers of unsuspecting visitors. This flaw operates under the common CWE-79 category of Cross-Site Scripting, where improperly validated input leads to code execution in the victim's browser context. The vulnerability's impact is amplified by the widespread adoption of the Hybrid theme, potentially affecting numerous WordPress installations simultaneously.
From an operational perspective, this vulnerability enables attackers to perform various malicious activities including session hijacking, defacement of affected websites, data theft from authenticated users, and redirection to malicious domains. The remote nature of the attack means that threat actors can exploit this vulnerability without requiring physical access to the target system or direct network connectivity to the server. Attackers can craft malicious URLs containing the cpage parameter with embedded scripts that execute when users navigate to affected pages, making this a particularly dangerous vulnerability for public-facing WordPress sites that rely on the Hybrid theme.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, specifically under the T1059.001 technique for Command and Scripting Interpreter and T1566.001 for Phishing. The vulnerability provides attackers with a means to establish persistent access through malicious scripts that can collect user credentials or redirect traffic. Organizations using affected versions of the Hybrid theme should immediately implement mitigations including updating to version 0.10 or later, implementing proper input validation, and deploying content security policies to limit the execution of unauthorized scripts. Additionally, web application firewalls can provide an additional layer of protection by filtering suspicious input patterns associated with XSS attacks. Regular security audits and monitoring of user input parameters remain critical defensive measures against similar vulnerabilities in web applications.