CVE-2023-1921 in WP Fastest Cache Plugin
Summary
by MITRE • 04/06/2023
The WP Fastest Cache plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.1.2. This is due to missing or incorrect nonce validation on the wpfc_start_cdn_integration_ajax_request_callback function. This makes it possible for unauthenticated attackers to change cdn settings 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 • 04/09/2026
The WP Fastest Cache plugin represents a widely used caching solution for WordPress websites, designed to improve site performance by storing static versions of web pages. This particular vulnerability affects versions up to and including 1.1.2, where a critical cross-site request forgery flaw exists within the plugin's ajax request handling mechanism. The vulnerability specifically targets the wpfc_start_cdn_integration_ajax_request_callback function which fails to properly validate nonce tokens, creating a significant security risk for affected WordPress installations.
The technical flaw stems from the absence of proper nonce validation in the ajax callback function that processes CDN integration requests. Nonce validation serves as a critical security mechanism that ensures requests originate from legitimate sources within the WordPress environment. Without this validation, attackers can construct malicious requests that appear to come from authenticated administrators, exploiting the trust relationship between the browser and the WordPress site. This vulnerability operates under the CWE-352 category, which specifically addresses cross-site request forgery weaknesses in web applications.
The operational impact of this vulnerability is substantial as it allows unauthenticated attackers to modify CDN settings without requiring valid credentials or administrative privileges. An attacker could potentially redirect CDN traffic to malicious servers, compromise content delivery, or disrupt service availability. The attack requires social engineering to trick administrators into clicking malicious links or visiting compromised websites, but once successful, the attacker gains the ability to modify critical CDN configuration parameters. This represents a significant risk to website owners as CDN settings directly impact content delivery, performance, and security posture of WordPress sites.
The vulnerability aligns with ATT&CK technique T1548.002 which covers abuse of group privileges, and more specifically addresses the broader category of privilege escalation through web application flaws. Organizations using affected plugin versions face potential data integrity compromise and service disruption risks. The attack vector relies on user interaction, making it particularly dangerous in environments where administrators frequently browse external sites or click on links from untrusted sources. This vulnerability demonstrates the critical importance of proper input validation and authentication mechanisms in web application development, particularly for plugins that handle sensitive administrative functions.
Mitigation strategies include immediate upgrade to the latest plugin version where the nonce validation has been properly implemented. Administrators should also implement additional security measures such as restricting access to administrative functions through network-level controls, monitoring for unusual CDN configuration changes, and conducting regular security audits of installed plugins. The WordPress security team recommends verifying plugin integrity through official sources and maintaining updated security practices including regular plugin updates, strong authentication mechanisms, and monitoring for suspicious administrative activities. Organizations should also consider implementing web application firewalls to detect and block potentially malicious requests targeting such vulnerabilities.