CVE-2021-24870: 
WordPress vulnerability analysis and mitigation

CVE-2021-24870 affects the WP Fastest Cache WordPress plugin versions before 0.9.5. The vulnerability was discovered during an internal audit and publicly disclosed on October 14, 2021. The issue exists in the plugin's wpfc_save_cdn_integration AJAX action, which lacks proper security controls (Jetpack Blog, WPScan).

The vulnerability stems from two main issues: a missing CSRF (Cross-Site Request Forgery) check in the wpfc_save_cdn_integration AJAX action, and improper sanitization and escaping of options available via this action. The vulnerability has been assigned a CVSS v3.1 score of 6.1 (Medium) and is classified as CWE-352 (Cross-Site Request Forgery) (NVD).

If successfully exploited, this vulnerability could allow attackers to make logged-in users with high privileges execute unintended actions and store Cross-Site Scripting (XSS) payloads on the affected website. This could potentially enable attackers to perform any action that the targeted administrator is allowed to do on the site (Jetpack Blog).

The vulnerability was patched in WP Fastest Cache version 0.9.5. Site administrators are strongly recommended to update to this version or later. Additionally, implementing a comprehensive security solution and maintaining regular security practices is advised (Jetpack Blog).

The vulnerability disclosure process involved some initial reluctance from the plugin authors to acknowledge the CSRF issue. However, after obtaining a second opinion from the WordPress plugin team, the developers addressed the vulnerability in version 0.9.5 (Jetpack Blog).