CVE-2021-4345 in uListing Plugin
Summary
by MITRE • 06/07/2023
The uListing plugin for WordPress is vulnerable to authorization bypass due to missing capability and nonce checks on the UlistingUserRole::save_role_api method in versions up to, and including, 1.6.6. This makes it possible for unauthenticated attackers to remove or add roles, and add capabilities.
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Analysis
by VulDB Data Team • 07/05/2023
The uListing plugin for WordPress represents a popular directory and listing solution that enables users to create and manage various types of listings on their websites. This vulnerability affects versions up to and including 1.6.6, creating a significant security risk for WordPress installations that utilize this plugin. The flaw resides within the UlistingUserRole::save_role_api method which handles role management operations through the plugin's administrative interface. The vulnerability stems from inadequate authorization controls that fail to properly verify user permissions before executing role modification functions.
The technical implementation of this vulnerability demonstrates a critical failure in access control mechanisms where the save_role_api method lacks proper capability checks and nonce validation. This absence of security controls allows unauthenticated attackers to exploit the method by directly calling the API endpoint without requiring valid user credentials or proper authorization. The vulnerability specifically targets the plugin's role management functionality, enabling attackers to perform unauthorized operations such as adding new roles, removing existing roles, and modifying capabilities assigned to different user roles. This represents a classic authorization bypass vulnerability that violates fundamental security principles of least privilege and proper access control enforcement.
From an operational impact perspective, this vulnerability creates a severe risk for WordPress administrators and site owners who rely on the uListing plugin for their directory functionality. Attackers can leverage this flaw to escalate their privileges within the WordPress environment, potentially gaining access to administrative functions or creating backdoor accounts with elevated permissions. The ability to modify user roles and capabilities can lead to complete compromise of the affected WordPress installation, allowing unauthorized individuals to manipulate the entire user access structure. This vulnerability particularly affects sites that have not properly configured additional security measures or network segmentation, making the attack surface more exposed.
The vulnerability aligns with CWE-863, which addresses "Incorrect Authorization" issues where the system fails to properly verify that the actor has the necessary permissions to perform a requested action. From the ATT&CK framework perspective, this represents a privilege escalation technique under the T1078 category, specifically targeting legitimate credentials and privileges within the WordPress environment. The lack of nonce validation also introduces potential for cross-site request forgery attacks, where attackers could manipulate role assignments through crafted requests. Organizations should immediately implement the recommended mitigation strategies including updating to the patched version of the uListing plugin, implementing additional authentication layers, and monitoring for suspicious administrative activities.
Mitigation efforts should prioritize immediate patching of the uListing plugin to version 1.6.7 or later, which addresses the capability and nonce validation issues. Security administrators should also implement proper input validation and output encoding practices, establish network-level restrictions on administrative endpoints, and deploy web application firewalls to monitor and block suspicious API requests. Additionally, regular security audits should be conducted to identify similar authorization bypass vulnerabilities in other plugins or custom code implementations. The vulnerability underscores the critical importance of proper authorization controls in WordPress plugins and highlights the need for comprehensive security testing during the development lifecycle to prevent such issues from reaching production environments.