The Check Plagiarism plugin for WordPress suffers from a missing authorization vulnerability identified as CVE-2025-11172, classified under CWE-862 (Missing Authorization). The vulnerability exists in the chk_plag_mine_plugin_wpse10500_admin_action() function, which fails to verify whether the authenticated user has the necessary capabilities before allowing modification of the plugin's API key. This flaw affects all versions up to and including 2.0. An attacker with at least Subscriber-level access to the WordPress site can exploit this vulnerability to update the API key without proper authorization. Since WordPress Subscriber roles typically have minimal privileges, this significantly lowers the barrier for exploitation. The vulnerability does not require user interaction and can be exploited remotely over the network. The CVSS 3.1 base score is 4.3 (medium), reflecting low impact on confidentiality and availability but a partial impact on integrity due to unauthorized modification of plugin settings. No patches or fixes have been published yet, and no known exploits have been observed in the wild. The vulnerability could be leveraged to disrupt plagiarism checking functionality or potentially redirect API calls, which might affect the reliability of plagiarism detection services. The issue highlights the importance of proper capability checks in WordPress plugin development to prevent unauthorized configuration changes by low-privilege users.

For European organizations, particularly those in education, publishing, and content creation sectors relying on the Check Plagiarism plugin, this vulnerability poses a risk to the integrity of plagiarism detection services. Unauthorized modification of the API key could lead to service disruption, inaccurate plagiarism reports, or potential misuse of API credentials. This could undermine trust in academic integrity systems and content validation processes. Although the vulnerability does not directly expose sensitive data or cause denial of service, the ability for low-privilege users to alter plugin configuration could facilitate further attacks or operational disruptions. Organizations with multi-user WordPress environments where users have Subscriber or higher roles are at increased risk. The lack of patches means the vulnerability remains exploitable until addressed, necessitating proactive mitigation. The impact is more pronounced in institutions with large numbers of authenticated users and where plagiarism checking is critical to operations.

1. Immediately audit and restrict user roles on WordPress sites using the Check Plagiarism plugin, ensuring only trusted users have Subscriber-level or higher access. 2. Implement monitoring and alerting for changes to the plugin’s API key or configuration settings to detect unauthorized modifications promptly. 3. Temporarily disable or uninstall the Check Plagiarism plugin if possible until a security patch is released. 4. Apply the principle of least privilege by reviewing and minimizing user permissions across the WordPress installation. 5. Use web application firewalls (WAFs) to monitor and block suspicious requests targeting the vulnerable function. 6. Stay informed on vendor updates and apply patches immediately once available. 7. Consider isolating critical WordPress instances or using separate environments for sensitive operations to limit exposure. 8. Conduct regular security assessments and penetration tests focusing on plugin vulnerabilities and authorization controls.