CVE-2021-4383 in WP Quick FrontEnd Editor Plugin
Summary
by MITRE • 06/07/2023
The WP Quick FrontEnd Editor plugin for WordPress is vulnerable to page content injection in versions up to, and including, 5.5. This is due to missing capability checks in the plugin's page-editing functionality. This makes it possible for low-authenticated attackers, such as subscribers, to edit/create any page or post on the blog.
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Analysis
by VulDB Data Team • 04/09/2026
The WP Quick FrontEnd Editor plugin for WordPress presents a critical authorization bypass vulnerability that undermines the fundamental security model of the platform. This vulnerability affects versions up to and including 5.5, where the plugin fails to implement proper capability checks during page editing operations. The flaw resides in the plugin's insufficient validation mechanisms that should normally restrict administrative functions to users with appropriate permissions. According to CWE-285, this represents an inadequate authorization control where the system does not properly verify that the requesting entity has sufficient privileges to perform the requested operation. The vulnerability creates a dangerous scenario where users with minimal privileges can execute actions typically restricted to administrators or editors, fundamentally compromising the role-based access control that WordPress relies upon for its security architecture.
The technical implementation of this vulnerability stems from the plugin's failure to validate user capabilities before processing page editing requests. When a user attempts to modify content through the front-end editor interface, the plugin should verify whether the authenticated user possesses the necessary permissions to perform such actions. However, the absence of proper capability checks means that any authenticated user, regardless of their role level, can submit requests that modify page content. This represents a classic case of insufficient input validation and authorization enforcement, where the plugin's security controls are bypassed through the omission of essential access control mechanisms. The vulnerability manifests when low-privileged users submit edit requests that are processed without proper verification of their authorization level, allowing them to manipulate content that should be restricted to higher-privileged users.
The operational impact of this vulnerability extends beyond simple content modification, creating potential vectors for more severe security breaches within WordPress environments. Attackers with subscriber-level access can leverage this vulnerability to inject malicious content, modify existing pages to include harmful links or scripts, or create new pages with unauthorized content that could be used for phishing or social engineering attacks. The ability to create or modify pages provides attackers with persistent attack surfaces that can be used to compromise other users or establish backdoors within the WordPress installation. This vulnerability directly impacts the integrity and availability of website content, as malicious actors can deface sites, inject malware, or manipulate content to serve their objectives. The attack surface is particularly concerning in multi-user environments where subscribers might be legitimate users whose credentials could be compromised through various means.
Security mitigations for this vulnerability should focus on immediate plugin updates and configuration reviews to prevent exploitation. Users should upgrade to the latest version of the WP Quick FrontEnd Editor plugin where the capability checks have been properly implemented and validated. System administrators should conduct thorough reviews of user roles and permissions to ensure that only authorized personnel have access to content editing functions. The implementation of additional security layers such as web application firewalls and content security policies can provide defense-in-depth measures against exploitation attempts. According to ATT&CK framework domain T1078, which covers valid accounts, this vulnerability demonstrates how attackers can leverage legitimate user accounts with insufficiently restricted permissions to gain unauthorized access to system resources. Regular security audits and monitoring of user activities can help detect anomalous behavior patterns that may indicate exploitation attempts, while proper logging of content modification activities enables forensic analysis and incident response procedures. Organizations should also consider implementing principle of least privilege practices to minimize the potential impact of such vulnerabilities across their WordPress installations.