CVE-2021-4387 in Opal Estate Plugin
Summary
by MITRE • 07/01/2023
The Opal Estate plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.6.11. This is due to missing or incorrect nonce validation on the opalestate_set_feature_property() and opalestate_remove_feature_property() functions. This makes it possible for unauthenticated attackers to set and remove featured properties via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 07/22/2023
The vulnerability identified as CVE-2021-4387 affects the Opal Estate plugin for WordPress, a popular real estate management solution that allows website administrators to list properties and manage real estate data. This particular flaw exists in plugin versions up to and including 1.6.11, making it a significant concern for WordPress site owners who rely on this specific plugin for their real estate listings. The vulnerability stems from inadequate security controls within the plugin's core functionality, specifically targeting the administrative features that manage property listings.
The technical flaw manifests in the opalestate_set_feature_property() and opalestate_remove_feature_property() functions which are designed to handle administrative actions related to property features. These functions lack proper nonce validation mechanisms that should be implemented to verify the authenticity of requests. A nonce is a unique value generated for each user session that ensures requests originate from legitimate administrative actions rather than maliciously crafted requests. Without this validation, attackers can forge requests that appear to come from authenticated administrators, effectively bypassing the normal security controls that protect these sensitive functions.
The operational impact of this Cross-Site Request Forgery vulnerability is substantial as it allows unauthenticated attackers to manipulate property listings without requiring any valid credentials. An attacker could potentially set any property as featured or remove featured status from properties, which could significantly impact a website's content presentation and potentially affect business operations. This vulnerability is particularly dangerous because it requires only social engineering to exploit, such as tricking an administrator into clicking a malicious link, making it accessible to attackers with minimal technical expertise. The consequences could include unauthorized content modification, potential SEO manipulation, and disruption of legitimate business operations.
This vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery weaknesses in software applications. The flaw demonstrates a failure to implement proper input validation and authentication checks as outlined in the OWASP Top Ten security risks. From an ATT&CK framework perspective, this represents a privilege escalation technique that allows attackers to perform administrative actions without proper authorization, potentially leading to further compromise of the affected WordPress installation. The vulnerability also relates to T1548.001, which covers abuse of cloud services and administrative access, and T1078, which addresses valid accounts usage for persistence and privilege escalation.
Organizations affected by this vulnerability should immediately update to the latest version of the Opal Estate plugin where the nonce validation has been properly implemented. Security administrators should also review their WordPress plugin management practices to ensure all installed plugins are regularly updated and monitored for security issues. Additional mitigations include implementing Content Security Policy headers to limit the scope of potential attacks, monitoring for unusual administrative activities, and conducting regular security audits of all installed plugins. The vulnerability also underscores the importance of proper security testing during plugin development, particularly focusing on authentication and authorization controls for administrative functions.