CVE-2021-4396: 
WordPress vulnerability analysis and mitigation

CVE-2021-4396 affects the Rucy plugin for WordPress versions up to and including 0.4.4. The vulnerability was discovered by Jerome Bruandet of NinTechNet and was publicly disclosed on July 1, 2023. This Cross-Site Request Forgery (CSRF) vulnerability exists due to missing or incorrect nonce validation in the save_rc_post_meta() function (NVD).

The vulnerability stems from improper security controls in the save_rc_post_meta() function within the Rucy WordPress plugin. The CVSS v3.1 base score is 4.3 (Medium) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N, indicating that the vulnerability requires user interaction but can be exploited remotely without authentication (Wordfence).

The vulnerability allows unauthenticated attackers to save post meta data through forged requests if they can trick a site administrator into performing specific actions, such as clicking on a malicious link (NVD).

Users should update the Rucy plugin to a version newer than 0.4.4 which contains the security fix. The vulnerability has been patched by implementing proper nonce validation in the affected function (WordPress).