The vulnerability identified as CVE-2025-65657 affects FeehiCMS version 2.1.1, specifically within its Ad Management functionality. It allows authenticated remote attackers to perform Remote Code Execution (RCE) by uploading crafted PHP files. The core issue stems from insufficient validation and sanitization of uploaded files, which are stored in locations where the server executes them. This lack of execution restrictions means that an attacker with valid credentials can upload a malicious PHP script that the server will run, thereby gaining the ability to execute arbitrary code remotely. The vulnerability is classified under CWE-77, which relates to improper neutralization of special elements used in a command ('Command Injection'). The CVSS v3.1 base score is 6.5, indicating a medium severity level. The vector string (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N) suggests that the attack can be performed remotely over the network with low attack complexity, no privileges required (though the description states authentication is needed, which may indicate a discrepancy), no user interaction, and impacts confidentiality and integrity partially but not availability. No patches or known exploits are currently documented, but the vulnerability's nature makes it a significant risk if left unaddressed. The attack surface is limited to authenticated users, which somewhat reduces the risk but does not eliminate it, especially if credential compromise is possible. The vulnerability could be leveraged to gain deeper access to the server, potentially leading to data theft, defacement, or pivoting to other internal systems.

For European organizations, the impact of this vulnerability can be substantial, especially for those relying on FeehiCMS 2.1.1 for web content management and advertising. Successful exploitation could lead to unauthorized code execution on web servers, enabling attackers to access sensitive data, modify content, or establish persistent backdoors. This threatens the confidentiality and integrity of organizational data and could damage reputation and trust. While availability is not directly impacted, secondary effects such as defacement or data leakage could disrupt business operations. Organizations in sectors with stringent data protection requirements, such as finance, healthcare, and government, face increased regulatory and compliance risks if exploited. Additionally, the vulnerability could be used as a foothold for further attacks within the network, increasing overall risk exposure. The requirement for authentication reduces the attack surface but does not eliminate risk, as credential theft or weak authentication mechanisms could facilitate exploitation. Given the medium severity, organizations should not underestimate the threat, especially since no patches are currently available, increasing the window of exposure.

To mitigate this vulnerability effectively, European organizations should first verify if they are using FeehiCMS version 2.1.1 and assess the exposure of the Ad Management module. Immediate steps include restricting file upload capabilities to trusted users only and implementing strict server-side validation and sanitization of uploaded files to ensure only safe file types are accepted. Employing allowlists for file extensions and MIME types, combined with scanning uploads for malicious content, can reduce risk. Configuring the web server to prevent execution of uploaded files in directories used for file storage is critical; for example, disabling PHP execution in upload directories via web server configuration. Monitoring logs for unusual upload activity or execution attempts can help detect exploitation attempts early. Organizations should also enforce strong authentication mechanisms, including multi-factor authentication, to reduce the risk of credential compromise. Network segmentation can limit the impact if exploitation occurs. Until an official patch is released, consider deploying Web Application Firewalls (WAFs) with custom rules to block suspicious upload patterns related to this vulnerability. Finally, maintain regular backups and have an incident response plan ready to address potential breaches.