CVE-2025-9544 is a vulnerability classified under CWE-862 (Missing Authorization) affecting the Doppler Forms WordPress plugin through version 2.5.1. The flaw arises because the plugin registers an AJAX action named 'install_extension' without verifying user capabilities or implementing nonce checks to prevent CSRF attacks. Consequently, any authenticated user, including those with the Subscriber role who typically have minimal permissions, can trigger this AJAX action to install and activate additional Doppler Forms plugins. The installation is limited to plugins whitelisted by the main Doppler Forms plugin, but this still allows unauthorized elevation of privileges and potential execution of malicious code or unauthorized functionality within the WordPress environment. The vulnerability does not require administrative privileges or user interaction beyond authentication, making exploitation straightforward in environments where users have Subscriber or higher roles. No CVSS score has been assigned yet, and no public exploits are known at this time. The lack of nonce and capability checks represents a fundamental security oversight, increasing the risk of privilege escalation and unauthorized plugin management on affected WordPress sites.

For European organizations, this vulnerability can lead to unauthorized privilege escalation, allowing low-privilege users to install and activate additional plugins that could compromise site integrity, confidentiality, and availability. This could result in data breaches, defacement, or the introduction of backdoors and malware. Organizations relying on Doppler Forms for critical business processes or customer interactions risk operational disruption and reputational damage. The impact is heightened in multi-user environments such as corporate intranets, educational institutions, or membership sites where many users have Subscriber-level access. The ability to install plugins without proper authorization can also facilitate lateral movement within the WordPress environment, potentially leading to full site compromise. Given the widespread use of WordPress across Europe, especially in SMEs and public sector websites, the threat could affect a broad range of sectors.

1. Immediately restrict access to the 'install_extension' AJAX action by implementing capability checks to ensure only trusted roles (e.g., administrators) can invoke it. 2. Implement nonce verification to protect against CSRF attacks on AJAX endpoints. 3. Monitor user roles and permissions closely, minimizing the number of users with roles above Subscriber unless necessary. 4. Disable or remove the Doppler Forms plugin if it is not essential until a patched version is released. 5. Apply security plugins or web application firewalls (WAFs) that can detect and block unauthorized AJAX requests targeting this vulnerability. 6. Conduct regular audits of installed plugins and their activation status to detect unauthorized changes. 7. Educate site administrators and users about the risks of privilege escalation and enforce strong authentication policies. 8. Stay alert for official patches or updates from the Doppler Forms plugin developers and apply them promptly once available.