CVE-2021-4096 in Fancy Product Designer Plugin
Summary
by MITRE • 04/20/2022
The Fancy Product Designer plugin for WordPress is vulnerable to Cross-Site Request Forgery via the FPD_Admin_Import class that makes it possible for attackers to upload malicious files that could be used to gain webshell access to a server in versions up to, and including, 4.7.5.
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Analysis
by VulDB Data Team • 04/27/2022
The Fancy Product Designer plugin for WordPress represents a widely used tool for creating customizable product designs on e-commerce websites, but it has been identified with a critical cross-site request forgery vulnerability that exposes installations to significant security risks. This vulnerability specifically affects versions up to and including 4.7.5, making it a persistent threat to numerous WordPress deployments that have not yet been updated to address the flaw. The vulnerability resides within the FPD_Admin_Import class, which handles file import operations and lacks proper authentication and validation mechanisms that should prevent unauthorized file uploads.
The technical flaw manifests through the absence of adequate CSRF protection measures in the import functionality, allowing attackers to craft malicious requests that appear to originate from authenticated administrators. This vulnerability stems from the plugin's failure to implement proper nonce validation and session management controls when processing file upload operations. Attackers can exploit this weakness by tricking administrators into executing malicious actions through social engineering or by leveraging existing access to the administration interface. The imported files can include malicious PHP scripts or other executable content that, when processed by the vulnerable plugin, can result in unauthorized code execution on the target server.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a potential pathway to achieve complete server compromise through webshell deployment. Once an attacker successfully uploads malicious files via the CSRF exploit, they can establish persistent access to the compromised WordPress installation, potentially leading to data theft, service disruption, or use as a pivot point for attacking other systems within the network. The vulnerability is particularly dangerous because it can be exploited without requiring administrative credentials, making it a significant concern for WordPress installations where administrators may not be consistently vigilant about security practices.
Security practitioners should recognize this vulnerability as a variant of CWE-352, which specifically addresses Cross-Site Request Forgery conditions in web applications. The attack vector aligns with techniques described in the ATT&CK framework under T1190 for exploiting vulnerabilities in web applications and T1059 for executing malicious code through web shells. Organizations should prioritize immediate patching of affected installations to prevent exploitation, while implementing additional security controls such as web application firewalls and monitoring for unusual file upload activities. The vulnerability also highlights the importance of proper input validation and authentication mechanisms in plugin development, emphasizing that third-party components can introduce significant security risks when not properly secured against common attack patterns.