CVE-2024-24399 is a high-severity arbitrary file upload vulnerability affecting LEPTON version 7.0.0. This vulnerability allows an authenticated attacker with high privileges to upload arbitrary PHP code to the backend/languages/index.php directory. The vulnerability is classified under CWE-434, which pertains to unrestricted file upload flaws. Exploitation requires network access (AV:N), low attack complexity (AC:L), and high privileges (PR:H), but no user interaction (UI:N). Successful exploitation can lead to full compromise of the affected system, as the attacker can execute arbitrary PHP code, potentially leading to complete confidentiality, integrity, and availability loss. The vulnerability is rated with a CVSS 3.1 score of 7.2, indicating a high impact. No known exploits are currently reported in the wild, and no official patches or vendor information are provided yet. The lack of vendor and product details suggests LEPTON is a lesser-known or niche CMS or web application framework, but the presence of a backend languages directory indicates it is used for multilingual content management or similar functionality.

For European organizations using LEPTON v7.0.0, this vulnerability poses a significant risk. An attacker who gains authenticated access—likely through compromised credentials or insider threat—can upload malicious PHP scripts, leading to remote code execution. This can result in data breaches, defacement, service disruption, or pivoting to internal networks. Confidential data, including personal data protected under GDPR, could be exposed or altered, leading to regulatory penalties and reputational damage. The ability to execute arbitrary code also threatens system availability and integrity, potentially causing downtime or manipulation of critical business processes. Since the vulnerability requires authentication, organizations with weak access controls or credential management are at higher risk. The absence of known exploits in the wild provides a window for proactive mitigation before widespread attacks occur.

European organizations should immediately audit their use of LEPTON CMS or related systems to identify any instances of version 7.0.0. Until an official patch is released, organizations should implement strict access controls and monitor authentication logs for suspicious activity. Restrict backend access to trusted IP ranges and enforce multi-factor authentication to reduce the risk of credential compromise. Employ web application firewalls (WAFs) with rules to detect and block file upload attempts to the backend/languages/index.php path. Conduct code reviews and penetration testing focused on file upload functionality. Additionally, implement file integrity monitoring on backend directories to detect unauthorized changes. Organizations should also prepare incident response plans specific to web shell or PHP code execution scenarios. Once a patch or vendor guidance is available, prioritize immediate deployment. Finally, consider isolating LEPTON instances in segmented network zones to limit lateral movement in case of compromise.