CVE-2021-4403: 
WordPress vulnerability analysis and mitigation

The Remove Schema plugin for WordPress (versions up to 1.5) contains a Cross-Site Request Forgery (CSRF) vulnerability identified as CVE-2021-4403. The vulnerability was discovered due to missing or incorrect nonce validation in the validate() function. The issue was disclosed on June 21, 2021, affecting all versions of the plugin up to and including version 1.5 (NVD).

The vulnerability stems from improper nonce validation in the plugin's validate() function. The CVSS v3.1 base score is 4.3 (MEDIUM) with a vector string of CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N. The issue was fixed in version 1.6 of the plugin by correcting the nonce check implementation (WordPress Patch).

The vulnerability allows unauthenticated attackers to modify the plugin's settings through forged requests if they can trick a site administrator into performing specific actions, such as clicking on a malicious link (NVD).

Users are advised to update the Remove Schema plugin to version 1.6 or later, which includes the security fix for the CSRF vulnerability. The update implements proper nonce validation to prevent unauthorized modifications to plugin settings (WordPress Patch).