CVE-2021-4381 in uListing Plugin
Summary
by MITRE • 06/07/2023
The uListing plugin for WordPress is vulnerable to authorization bypass via wp_route due to missing capability checks, and a missing security nonce, in the StmListingSingleLayout::import_new_layout method in versions up to, and including, 1.6.6. This makes it possible for unauthenticated attackers to change any WordPress option in the database.
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Analysis
by VulDB Data Team • 04/09/2026
The uListing WordPress plugin presents a critical authorization bypass vulnerability that undermines fundamental security controls within the WordPress ecosystem. This vulnerability exists in versions up to and including 1.6.6, where the plugin fails to implement proper capability checks and security nonces in its import_new_layout method. The flaw specifically affects the StmListingSingleLayout::import_new_layout functionality, creating a pathway for unauthenticated attackers to execute arbitrary actions within the WordPress administration interface. The vulnerability stems from inadequate input validation and missing authentication mechanisms that should normally prevent unauthorized modifications to core WordPress settings. According to CWE-863, this represents a failure to enforce proper access control, allowing attackers to bypass the intended security boundaries that separate user roles and administrative functions.
The technical exploitation of this vulnerability occurs through the wp_route parameter which serves as an entry point for the authorization bypass. Attackers can craft malicious requests that leverage this parameter to manipulate WordPress options without requiring valid authentication credentials or administrative privileges. The absence of security nonce validation further compounds the issue, eliminating the protection that nonce-based mechanisms typically provide against cross-site request forgery attacks. This vulnerability directly enables attackers to modify critical WordPress configuration settings, potentially leading to complete system compromise. The flaw operates at the core level of WordPress administration, where unauthorized modifications can fundamentally alter the site's behavior and security posture. This type of vulnerability aligns with ATT&CK technique T1078 which covers valid accounts usage, as attackers can leverage the bypass to gain elevated privileges without proper authentication.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete database manipulation capabilities. Attackers can modify WordPress options, potentially changing core settings such as admin URLs, plugin configurations, or even disabling security features that protect against further exploitation. The vulnerability affects any WordPress installation running the affected uListing plugin version, making it particularly dangerous given the widespread use of WordPress and its plugins. This authorization bypass creates a persistent threat vector that remains active until the plugin is updated or the vulnerability is patched. The lack of proper capability checks means that any user, authenticated or not, can execute administrative functions through the vulnerable import_new_layout method, fundamentally undermining the principle of least privilege that governs secure system design.
Mitigation strategies must focus on immediate plugin updates to versions that address the authorization bypass and nonce validation issues. System administrators should implement network-level protections such as firewall rules that restrict access to wp-admin endpoints and monitor for unusual patterns of wp_route parameter usage. Regular security audits should verify that all WordPress plugins maintain proper authentication mechanisms and capability checks. The vulnerability demonstrates the critical importance of implementing security nonces for all administrative actions, as recommended by WordPress security best practices and aligned with CWE-352 standards for CSRF protection. Organizations should also consider implementing additional monitoring for unauthorized WordPress option changes and establish automated patch management processes to ensure rapid response to similar vulnerabilities. The incident highlights the necessity of comprehensive security testing for plugin developers and the importance of adhering to WordPress security guidelines to prevent similar authorization bypass scenarios in the future.