CVE-2018-20155 in WP Maintenance Mode Plugin
Summary
by MITRE
The WP Maintenance Mode plugin before 2.0.7 for WordPress allows remote authenticated subscriber users to bypass intended access restrictions on changes to plugin settings.
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Analysis
by VulDB Data Team • 04/21/2020
The WP Maintenance Mode plugin vulnerability represents a critical access control flaw that undermines the security posture of WordPress installations. This issue affects versions prior to 2.0.7 and specifically targets the plugin's permission handling mechanisms. The vulnerability enables authenticated users with subscriber-level privileges to escalate their access rights and modify critical plugin configurations that should be restricted to administrators or higher-level users. The flaw stems from insufficient validation of user roles and capabilities within the plugin's settings management interface, creating an unauthorized access vector that directly contradicts standard security practices for content management systems.
The technical implementation of this vulnerability demonstrates a clear failure in privilege enforcement mechanisms within the WordPress plugin architecture. Subscribers typically possess minimal capabilities within WordPress systems, yet this flaw allows them to bypass intended restrictions and gain access to administrative functions. The vulnerability operates through improper capability checks that fail to verify whether the requesting user possesses sufficient privileges to modify plugin settings. This type of flaw falls under the CWE-284 access control weakness category, specifically addressing inadequate permissions and privileges within web applications. The vulnerability's exploitation requires only authentication as a subscriber user, making it particularly dangerous as it can be leveraged by malicious insiders or compromised low-privilege accounts.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential system compromise and service disruption. An attacker with subscriber privileges could modify maintenance mode settings to disable security features, redirect traffic, or create backdoor access points within the WordPress installation. This capability could lead to complete system compromise, especially when combined with other vulnerabilities or when the maintenance mode plugin is used in conjunction with other security-critical functions. The vulnerability also violates fundamental security principles outlined in the ATT&CK framework under privilege escalation techniques, where adversaries seek to gain higher-level permissions through weaknesses in access control implementations.
Mitigation strategies for this vulnerability require immediate plugin updates to version 2.0.7 or later, which address the core access control flaw through proper capability validation. Administrators should also implement additional monitoring of plugin configuration changes to detect unauthorized modifications. The vulnerability highlights the importance of regular security audits and proper input validation within WordPress plugins. Organizations should consider implementing role-based access controls that enforce the principle of least privilege and regularly review user permissions. Security best practices dictate that all WordPress plugins should undergo thorough security testing, particularly those that handle administrative functions or modify core system configurations. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date software components and implementing robust access control mechanisms throughout web applications.