CVE-2022-45009 in Online Leave Management System
Summary
by MITRE • 12/07/2022
Online Leave Management System v1.0 was discovered to contain an arbitrary file upload vulnerability at /leave_system/classes/SystemSettings.php?f=update_settings. This vulnerability allows attackers to execute arbitrary code via a crafted PHP file.
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Analysis
by VulDB Data Team • 04/23/2025
The Online Leave Management System version 1.0 presents a critical arbitrary file upload vulnerability that fundamentally compromises the security posture of the application. This vulnerability exists within the SystemSettings.php file at the specific endpoint /leave_system/classes/SystemSettings.php?f=update_settings, where the application fails to properly validate or sanitize file uploads. The flaw enables remote attackers to bypass security controls and upload malicious PHP files directly to the server, creating a persistent backdoor for unauthorized access and execution of arbitrary code. The vulnerability represents a severe configuration oversight that directly violates fundamental web application security principles and allows for complete system compromise.
The technical implementation of this vulnerability stems from inadequate input validation and improper file handling mechanisms within the application's file upload functionality. When users attempt to update system settings through the designated endpoint, the application does not perform sufficient checks on uploaded files to ensure they conform to expected formats and content types. This absence of proper validation creates an exploitable condition where attackers can upload PHP scripts that execute with the privileges of the web server process. The vulnerability aligns with CWE-434, which specifically addresses insecure file upload handling, and demonstrates how insufficient access controls and input sanitization can lead to complete system compromise. Attackers can leverage this flaw to upload web shells, reverse shells, or other malicious payloads that persist across system reboots and remain undetected by standard monitoring systems.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete control over the affected server and its underlying resources. Once a malicious PHP file is successfully uploaded, attackers can execute commands remotely, access sensitive data, modify system configurations, and establish persistent backdoors for long-term access. The vulnerability affects the confidentiality, integrity, and availability of the entire leave management system, potentially exposing employee leave records, personal information, and system credentials. The consequences include data breaches, system downtime, regulatory compliance violations, and potential lateral movement within network environments where the vulnerable system resides. This vulnerability also enables attackers to use the compromised system as a launching point for attacking other networked systems through privilege escalation and lateral movement techniques.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements. The most critical immediate action involves implementing proper file type validation, content checking, and secure file storage practices within the application code. All file uploads should be validated against a whitelist of permitted extensions, and uploaded files should be stored outside the web root directory with restricted permissions. The system should implement proper MIME type checking, file content analysis, and random naming conventions for uploaded files to prevent predictable paths. Organizations should also deploy web application firewalls, implement network segmentation, and establish comprehensive monitoring systems to detect unauthorized file upload attempts. This vulnerability demonstrates the importance of following secure coding practices and adhering to industry standards such as the OWASP Top Ten and NIST Cybersecurity Framework to prevent similar issues from occurring in production environments. Regular security assessments, code reviews, and vulnerability scanning should be implemented to identify and remediate similar weaknesses before they can be exploited by malicious actors.