CVE-2021-4360 in Controlled Admin Access Plugin
Summary
by MITRE • 06/07/2023
The Controlled Admin Access plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 1.5.5 by not properly restricting access to the configuration page. This makes it possible for attackers to create a new administrator role with unrestricted access.
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Analysis
by VulDB Data Team • 07/05/2023
The Controlled Admin Access plugin for WordPress presents a critical privilege escalation vulnerability identified as CVE-2021-4360 affecting versions through 1.5.5. This vulnerability stems from inadequate access control mechanisms within the plugin's configuration page, creating a pathway for unauthorized users to gain elevated privileges. The flaw allows attackers to bypass intended security restrictions and establish new administrator accounts with unrestricted access to the WordPress installation. The vulnerability specifically targets the plugin's permission handling system, where proper user role validation fails to prevent unauthorized modifications to administrative configurations.
The technical implementation of this vulnerability resides in the plugin's failure to enforce proper authentication checks when accessing sensitive configuration endpoints. According to CWE-285, this represents an improper authorization issue where the system does not adequately verify user permissions before granting access to administrative functions. The flaw operates at the application layer where the plugin fails to implement robust access control measures that should prevent users without appropriate privileges from modifying core system settings. Attackers can exploit this by manipulating the plugin's interface to create new administrative accounts, effectively compromising the entire WordPress installation.
The operational impact of CVE-2021-4360 extends beyond simple privilege escalation, as it enables full administrative control over the compromised WordPress site. Once an attacker successfully exploits this vulnerability, they can modify content, install malicious plugins, access user data, and potentially use the compromised site as a launching point for further attacks within the network. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts used for lateral movement and persistence. The compromised administrative account provides attackers with unrestricted access to all WordPress features and data, making it a highly valuable target for threat actors seeking long-term access to web applications.
Security mitigations for this vulnerability include immediate patching of the Controlled Admin Access plugin to version 1.5.6 or later, which contains the necessary access control fixes. Organizations should also implement network segmentation and monitoring to detect unauthorized access attempts to WordPress administrative interfaces. Regular security audits of installed plugins and themes are essential to identify similar access control flaws. Additionally, implementing multi-factor authentication for administrative accounts and limiting direct access to administrative interfaces through firewalls can provide additional defense layers. The vulnerability demonstrates the critical importance of proper access control implementation in web applications, particularly those handling user authentication and authorization functions.