CVE-2025-15423 is a vulnerability identified in EmpireSoft's EmpireCMS product, specifically affecting version 8.0. The issue resides in the CheckSaveTranFiletype function within the file e/class/connect.php, which fails to properly validate uploaded files, allowing attackers to perform unrestricted file uploads. This vulnerability can be exploited remotely without user interaction and with low attack complexity, although it requires limited privileges on the system. The unrestricted upload capability can be leveraged to upload malicious scripts or web shells, potentially leading to remote code execution, website defacement, data exfiltration, or further compromise of the underlying server. The vulnerability has been publicly disclosed, but the vendor has not responded or released patches, increasing the urgency for organizations to implement alternative mitigations. The CVSS 4.0 score of 5.3 reflects a medium severity, considering the ease of exploitation and potential impact on confidentiality, integrity, and availability. The vulnerability does not require user interaction and affects a widely used content management system, making it a significant concern for organizations relying on EmpireCMS for web content delivery.

For European organizations, the impact of this vulnerability can be substantial. EmpireCMS is used by various enterprises and government entities for managing web content, so exploitation could lead to unauthorized access to sensitive data, website defacement, or disruption of online services. Attackers could deploy web shells to maintain persistent access, facilitating further attacks such as data theft, ransomware deployment, or lateral movement within networks. The lack of vendor patches increases the risk exposure, especially for organizations that cannot quickly migrate or replace the CMS. Additionally, compromised websites can damage organizational reputation and lead to regulatory penalties under GDPR if personal data is exposed. The medium severity rating suggests moderate but tangible risks to confidentiality, integrity, and availability, particularly for organizations with public-facing web infrastructure running EmpireCMS 8.0.

Given the absence of official patches, European organizations should implement the following specific mitigations: 1) Immediately restrict file upload permissions on the web server to the minimum necessary, ideally disabling uploads if not required. 2) Deploy a web application firewall (WAF) with custom rules to detect and block suspicious file upload attempts targeting the vulnerable function. 3) Conduct thorough code reviews and implement custom validation to restrict allowed file types and sanitize file names in the upload process. 4) Monitor web server logs and file system changes for indicators of compromise, such as unexpected file uploads or execution of unknown scripts. 5) Isolate the CMS environment using network segmentation to limit potential lateral movement if compromised. 6) Plan for migration to a patched or alternative CMS solution as a long-term remediation. 7) Educate IT and security teams about this vulnerability and ensure incident response plans include scenarios involving web shell detection and removal.