CVE-2012-3383 in WordPress
Summary
by MITRE
The map_meta_cap function in wp-includes/capabilities.php in WordPress 3.4.x before 3.4.2, when the multisite feature is enabled, does not properly assign the unfiltered_html capability, which allows remote authenticated users to bypass intended access restrictions and conduct cross-site scripting (XSS) attacks by leveraging the Administrator or Editor role and composing crafted text.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability described in CVE-2012-3383 represents a critical access control flaw within the WordPress content management system that specifically impacts versions 3.4.x prior to 3.4.2 when multi-site functionality is enabled. This issue resides within the map_meta_cap function located in the wp-includes/capabilities.php file, which serves as the core mechanism for determining user capabilities and permissions within the WordPress ecosystem. The flaw stems from improper handling of the unfiltered_html capability, a privilege that should normally be restricted to users with elevated privileges such as administrators or editors. When this capability is not properly assigned, it creates a dangerous loophole that allows authenticated users to bypass intended security restrictions.
The technical nature of this vulnerability can be categorized under CWE-284, which deals with improper access control mechanisms, and more specifically relates to improper privilege management within the WordPress security framework. The vulnerability manifests when users with Administrator or Editor roles attempt to compose content that includes crafted text elements designed to exploit the missing capability check. This flaw enables attackers to inject malicious scripts into the system, effectively bypassing the normal content filtering mechanisms that should prevent such code execution. The issue is particularly dangerous because it leverages existing user roles that are typically granted legitimate access to content management functions, making the attack vector more subtle and harder to detect.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables remote authenticated users to conduct cross-site scripting attacks that can have severe consequences for both administrators and end users. When exploited, this vulnerability allows attackers to inject malicious JavaScript code that can execute in the context of other users' browsers, potentially leading to session hijacking, data theft, or further compromise of the WordPress installation. The attack requires only authenticated access with Editor or Administrator privileges, which are often granted to trusted users within WordPress environments, making the vulnerability particularly concerning for organizations that rely heavily on WordPress for their web presence. The XSS payload could be used to steal cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users.
Mitigation strategies for this vulnerability should focus on immediate patching of WordPress installations to version 3.4.2 or later, which contains the necessary fixes for the capability assignment issue. Organizations should also implement comprehensive monitoring of user activities, particularly around content creation and editing functions, to detect potential exploitation attempts. Security measures should include regular security audits of WordPress installations, ensuring that user roles and capabilities are properly configured, and implementing additional layers of protection such as content security policies and web application firewalls. The remediation process must also involve verifying that all WordPress installations are updated to the latest stable versions and that proper access control policies are enforced. Additionally, administrators should review and restrict user capabilities appropriately, ensuring that only trusted users receive elevated privileges, and that regular security assessments are conducted to identify and address similar vulnerabilities in the WordPress core and associated plugins or themes.