CVE-2020-36740 in Radio Buttons for Taxonomies Plugin
Summary
by MITRE • 07/01/2023
The Radio Buttons for Taxonomies plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.5. This is due to missing or incorrect nonce validation on the save_single_term() function. This makes it possible for unauthenticated attackers to save terms via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/22/2023
The Radio Buttons for Taxonomies plugin for WordPress presents a critical cross-site request forgery vulnerability identified as CVE-2020-36740 affecting versions up to and including 2.0.5. This vulnerability resides within the plugin's handling of taxonomy term management operations and represents a significant security weakness that could compromise WordPress site integrity. The flaw specifically manifests in the save_single_term() function where proper nonce validation is either absent or incorrectly implemented, creating an exploitable condition that undermines the plugin's security controls. The vulnerability classification aligns with CWE-352, which specifically addresses cross-site request forgery weaknesses in web applications, and corresponds to ATT&CK technique T1213.002 related to data from information repositories. The absence of proper nonce validation creates a scenario where attackers can manipulate taxonomy terms without proper authorization, potentially leading to unauthorized modifications of site content and structure.
The technical implementation of this vulnerability stems from the plugin's failure to validate cryptographic nonces during term saving operations. Nonces serve as one-time tokens that verify the authenticity of requests and prevent unauthorized actions from being executed on behalf of authenticated users. In this case, the save_single_term() function lacks proper verification of these security tokens, allowing attackers to construct malicious requests that appear legitimate to the WordPress application. When an administrator performs actions such as clicking on a malicious link or visiting a compromised webpage, the forged request can execute term saving operations without the administrator's knowledge or consent. This makes the vulnerability particularly dangerous as it leverages social engineering techniques to bypass traditional authentication mechanisms and can result in unauthorized modifications to taxonomy structures that may impact site functionality and content organization.
The operational impact of this vulnerability extends beyond simple term manipulation and could enable attackers to fundamentally alter site taxonomy structures, potentially affecting SEO rankings, content organization, and user experience. An attacker could exploit this vulnerability to add malicious terms, modify existing taxonomy relationships, or potentially create new taxonomies that could be used for further attacks. The unauthenticated nature of the attack means that no prior access to the WordPress admin panel is required, making it particularly concerning for sites with active administrators who may be tricked into visiting malicious websites. The vulnerability's exploitation requires minimal technical skill and can be automated, making it attractive to threat actors seeking to compromise WordPress sites. This weakness could also serve as a stepping stone for more sophisticated attacks, as taxonomy modifications might be used to hide malicious content or manipulate site behavior in ways that could persist even after the initial compromise is detected.
Mitigation strategies for this vulnerability should prioritize immediate plugin updates to versions that address the nonce validation issue, as this represents the most direct solution to the problem. Administrators should also implement additional security measures such as monitoring for unusual taxonomy changes and implementing proper user access controls to limit who can perform term modifications. The WordPress security community recommends that all site administrators regularly update their plugins and themes to ensure they are protected against known vulnerabilities, with particular attention to plugins that handle administrative functions and data modifications. Organizations should also consider implementing web application firewalls and security monitoring solutions that can detect and prevent CSRF attacks, while maintaining regular security audits to identify and remediate similar vulnerabilities across their WordPress installations. The vulnerability underscores the importance of proper security testing and validation of authentication mechanisms, particularly in plugins that handle administrative functions and user data modifications.