CVE-2025-25224 in LuxCal Web Calendar
Summary
by MITRE • 02/18/2025
The LuxCal Web Calendar prior to 5.3.3M (MySQL version) and prior to 5.3.3L (SQLite version) contains a missing authentication vulnerability in dloader.php. If this vulnerability is exploited, arbitrary files on a server may be obtained.
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Analysis
by VulDB Data Team • 09/15/2025
The vulnerability identified as CVE-2025-25224 affects the LuxCal Web Calendar application across its MySQL and SQLite variants, specifically impacting versions prior to 5.3.3M and 5.3.3L respectively. This represents a critical security flaw that undermines the application's access control mechanisms, creating a pathway for unauthorized file retrieval from the affected server infrastructure. The vulnerability resides within the dloader.php component of the calendar system, which serves as a file loading utility that should normally enforce strict authentication protocols before granting access to server resources. The absence of proper authentication checks in this module creates an exploitable condition where malicious actors can bypass normal access controls and directly access files that should remain protected within the server's file system.
This missing authentication vulnerability falls under the CWE-287 category of inadequate authentication, which is classified as a fundamental weakness in application security where authentication mechanisms fail to properly verify the identity of users attempting to access protected resources. The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to potentially obtain sensitive files including configuration data, database credentials, application source code, and other potentially compromising information that could be used for further exploitation. The attack surface is particularly concerning because it allows arbitrary file retrieval, meaning that an attacker can potentially access any file that the web server has permission to read, which could include database backup files, administrative configuration settings, or even other applications running on the same server infrastructure.
The exploitation of this vulnerability aligns with techniques described in the ATT&CK framework under the T1078 adversary technique for Valid Accounts, where attackers leverage compromised or improperly configured access controls to gain unauthorized access to systems. The impact on system security is significant as it undermines the principle of least privilege and allows for potential lateral movement within the network if the affected server hosts other sensitive applications or data. Organizations using affected versions of LuxCal Web Calendar face heightened risk of data breaches, system compromise, and potential regulatory compliance violations, particularly in environments where the calendar application may have access to sensitive organizational data or where it shares infrastructure with other critical systems. The vulnerability represents a clear failure in the security design of the application's file access mechanisms and demonstrates the importance of implementing proper authentication checks for all file handling operations.
The recommended mitigation strategy involves immediate upgrade to the patched versions 5.3.3M for MySQL installations and 5.3.3L for SQLite installations, which should contain proper authentication mechanisms for the dloader.php component. Additionally, system administrators should implement network segmentation to limit access to the calendar application and its underlying server infrastructure, ensuring that only authorized users and systems can reach the vulnerable endpoints. Regular security audits and penetration testing should be conducted to identify similar authentication gaps in other applications and systems within the organization's infrastructure. Organizations should also consider implementing web application firewalls to monitor and filter requests to the vulnerable dloader.php endpoint, providing an additional layer of protection against exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper access control implementation and the necessity of conducting thorough security reviews of all application components, particularly those handling file operations and user access.