CVE-2011-5270 in WordPress
Summary
by MITRE
wp-admin/press-this.php in WordPress before 3.0.6 does not enforce the publish_posts capability requirement, which allows remote authenticated users to perform publish actions by leveraging the Contributor role.
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Analysis
by VulDB Data Team • 06/09/2021
The vulnerability identified as CVE-2011-5270 represents a critical authorization flaw within the WordPress content management system affecting versions prior to 3.0.6. This issue specifically targets the press-this.php administrative script located within the wp-admin directory structure, which serves as a quick publishing tool for users to create and schedule posts directly from external sources. The flaw stems from inadequate capability verification within the script's access control mechanisms, creating a pathway for unauthorized privilege escalation.
The technical nature of this vulnerability lies in the absence of proper capability checks within the press-this.php script. WordPress employs a role-based access control system where different user roles possess distinct sets of permissions and capabilities. The publish_posts capability is specifically designed to grant users the authority to publish posts directly to the site, a privilege typically reserved for editors and administrators. However, the press-this.php script fails to validate whether the authenticated user possesses this essential capability before executing publish operations, effectively bypassing the intended access controls.
This vulnerability has significant operational implications for WordPress installations, particularly those utilizing the Contributor role for content authors who should not have publishing privileges. Attackers exploiting this flaw can leverage their Contributor-level access to perform publish actions that should require higher privileges, potentially leading to unauthorized content publication, spam injection, or malicious content deployment. The impact extends beyond simple privilege escalation as it undermines the entire permission model that WordPress relies upon for content management security.
The vulnerability directly maps to CWE-284, which addresses improper access control issues in software systems, specifically targeting inadequate authorization checks. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1078.004, which involves legitimate credentials abuse through the exploitation of role-based access control weaknesses. The flaw demonstrates a classic case of insufficient input validation and access control enforcement, where the system fails to properly verify user permissions before executing privileged operations.
Organizations affected by this vulnerability should immediately upgrade to WordPress version 3.0.6 or later, which contains the necessary patches to enforce proper capability checks. Additionally, administrators should conduct comprehensive audits of user roles and permissions to ensure that contributors and other lower-privilege users do not possess unintended publishing capabilities. Implementing network monitoring solutions and access control logging can help detect potential exploitation attempts. Security teams should also consider implementing additional security layers such as web application firewalls and regular security scanning to identify similar authorization flaws across the WordPress installation and related components.