CVE-2025-9415 is a medium-severity vulnerability affecting GreenCMS version 2.3.0603 and earlier. The vulnerability exists in the file /index.php?m=admin&c=media&a=fileconnect, specifically in the handling of the upload[] argument. This flaw allows an attacker to perform an unrestricted file upload remotely without authentication or user interaction. The unrestricted upload means that an attacker can upload arbitrary files, potentially including malicious scripts or executables, which could lead to remote code execution, website defacement, data theft, or further compromise of the affected system. The vulnerability is present in a product that is no longer supported by its maintainer, meaning no official patches or security updates are available. Although the CVSS 4.0 score is 5.3 (medium), the exploitability is relatively straightforward due to no required privileges or user interaction, and the impact on confidentiality, integrity, and availability is low to limited but still significant given the ability to upload arbitrary files. The vulnerability is publicly known, and exploits exist, although no widespread exploitation has been reported yet. The lack of vendor support increases the risk for organizations still using GreenCMS 2.3.0603 or earlier, as they must rely on workarounds or third-party mitigations to protect their systems.

For European organizations, this vulnerability poses a moderate risk, especially for those using GreenCMS as their content management system. Successful exploitation could allow attackers to upload malicious payloads, leading to website defacement, data leakage, or pivoting into internal networks. This could disrupt business operations, damage reputation, and potentially expose sensitive customer or corporate data. Since GreenCMS is no longer supported, organizations cannot rely on vendor patches, increasing their exposure. The impact is particularly relevant for small to medium enterprises or public sector organizations that may still use legacy or unsupported CMS platforms. Additionally, regulatory compliance requirements such as GDPR impose strict data protection obligations, and a breach resulting from this vulnerability could lead to legal and financial penalties. The remote and unauthenticated nature of the exploit increases the likelihood of attacks, especially if the affected systems are internet-facing.

Given the lack of official patches, European organizations should consider the following specific mitigation strategies: 1) Immediately audit all GreenCMS installations to identify affected versions. 2) If possible, upgrade to a supported CMS platform or migrate content to a modern, actively maintained system. 3) Implement strict web application firewall (WAF) rules to block suspicious file upload attempts targeting the vulnerable endpoint, specifically filtering requests to /index.php with parameters m=admin, c=media, a=fileconnect and upload[] arguments. 4) Restrict access to the admin media upload interface by IP whitelisting or VPN-only access to reduce exposure. 5) Employ file integrity monitoring to detect unauthorized file uploads or modifications. 6) Disable or restrict file execution permissions in upload directories to prevent execution of malicious scripts. 7) Conduct regular security scans and penetration tests to detect exploitation attempts. 8) Monitor logs for unusual activity related to file uploads or admin interface access. 9) Educate IT staff about the risks of using unsupported software and the importance of timely upgrades. These targeted actions will help mitigate the risk despite the absence of official patches.