CVE-2025-10499 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the WordPress plugin 'Ninja Forms – The Contact Form Builder That Grows With You' developed by kstover. This vulnerability exists in all versions up to and including 3.12.0 due to missing or incorrect nonce validation in the maybe_opt_in() function. Nonces in WordPress are security tokens used to verify that requests are intentional and originate from legitimate users. The absence or improper implementation of nonce validation allows an unauthenticated attacker to craft a malicious request that, when executed by an authenticated site administrator (e.g., by clicking a link), can cause the site to opt into usage statistics collection without the administrator's consent. While this action does not directly compromise site confidentiality or availability, it represents an integrity issue by altering site settings without authorization. The vulnerability requires user interaction (the administrator must perform an action such as clicking a link) and does not require any prior authentication by the attacker. The CVSS v3.1 base score is 4.3 (medium severity), reflecting the limited impact and the need for user interaction. No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability is categorized under CWE-352, which is a common web application security weakness related to CSRF attacks.

For European organizations using WordPress sites with the Ninja Forms plugin, this vulnerability could lead to unauthorized changes in plugin settings, specifically opting the site into usage statistics collection. While this may seem minor, it could have privacy implications, especially under the GDPR framework, as it may result in unintended data sharing or telemetry without explicit consent. Additionally, this vulnerability could be leveraged as a stepping stone in more complex attack chains, potentially undermining trust in site integrity. Organizations with high compliance requirements or those handling sensitive user data may face reputational damage or regulatory scrutiny if such unauthorized changes are detected. The requirement for administrator interaction limits the scope but does not eliminate risk, especially in environments where administrators may be targeted via phishing or social engineering campaigns.

To mitigate this vulnerability, organizations should: 1) Immediately update the Ninja Forms plugin to a version that addresses this CSRF issue once a patch is released. In the absence of an official patch, consider temporarily disabling the plugin or restricting its usage to trusted administrators only. 2) Implement strict administrative access controls and enforce the principle of least privilege to minimize the number of users who can perform sensitive actions. 3) Educate administrators about phishing and social engineering risks, emphasizing caution before clicking on unsolicited links, especially those that could trigger site configuration changes. 4) Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious CSRF attempts targeting the maybe_opt_in() function or related endpoints. 5) Monitor site configurations and logs for unexpected changes in plugin settings or opt-in statuses to detect potential exploitation attempts early. 6) Consider adding additional nonce or token validation layers at the application or server level if feasible, to compensate for the plugin's missing checks.