CVE-2025-13136 identifies a missing authorization vulnerability (CWE-862) in the GSheetConnector For Ninja Forms plugin for WordPress, affecting all versions up to and including 2.0.1. The vulnerability stems from the absence of a proper capability check on the 'njform-google-sheet-config' administrative page, which controls the integration between Ninja Forms and Google Sheets. This flaw allows any authenticated user with at least Subscriber-level privileges to access this configuration page and retrieve sensitive system information that should normally be restricted to higher privilege roles such as administrators. The vulnerability does not require user interaction and can be exploited remotely over the network. The CVSS 3.1 base score is 4.3, indicating a medium severity level, with the vector AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, meaning the attack vector is network-based, with low attack complexity, requiring low privileges but no user interaction, and impacts confidentiality only. Although the vulnerability does not allow modification or disruption of data or services, unauthorized disclosure of system information could aid attackers in further reconnaissance or targeted attacks. No patches or exploits are currently publicly available, but the vulnerability is published and should be addressed promptly. The vulnerability is particularly relevant for organizations using WordPress sites with the Ninja Forms plugin and the GSheetConnector add-on, especially where multiple users have Subscriber-level access, which is common in content management scenarios.

For European organizations, this vulnerability poses a moderate risk primarily to confidentiality. Unauthorized users with minimal privileges can access sensitive configuration data, potentially exposing internal system details or integration credentials. This information leakage can facilitate further attacks such as privilege escalation, targeted phishing, or lateral movement within the network. Organizations relying on WordPress for customer-facing or internal forms, especially those integrating Ninja Forms with Google Sheets, may find their data privacy compromised. Although the vulnerability does not directly affect data integrity or availability, the exposure of configuration details can undermine trust and compliance with data protection regulations such as GDPR. The impact is heightened in environments where many users have Subscriber-level access, increasing the attack surface. Since no known exploits are in the wild, the immediate threat is moderate, but the risk escalates if attackers develop exploit code. European sectors with high WordPress usage, including SMEs, media, education, and public services, should be particularly vigilant.

1. Monitor for official patches or updates from the plugin vendor and apply them immediately once available. 2. Until patches are released, implement custom access controls to restrict access to the 'njform-google-sheet-config' page, such as using WordPress role management plugins to limit Subscriber-level user capabilities or employing web application firewalls (WAFs) to block unauthorized requests. 3. Audit user roles and permissions regularly to ensure that only trusted users have Subscriber-level or higher access, minimizing the number of accounts that could exploit this vulnerability. 4. Employ security plugins that can detect unauthorized access attempts or unusual activity on administrative pages. 5. Consider disabling or removing the GSheetConnector plugin if it is not essential to reduce the attack surface. 6. Educate users about the risks of privilege misuse and enforce strong authentication policies to prevent account compromise. 7. Monitor logs for suspicious access patterns to the affected configuration page to detect potential exploitation attempts early.