CVE-2019-15751 in Six
Summary
by MITRE
An unrestricted file upload vulnerability in SITOS six Build v6.2.1 allows remote attackers to execute arbitrary code by uploading a SCORM file with an executable extension. This allows an unauthenticated attacker to upload a malicious file (containing PHP code to execute operating system commands) to the web root of the application.
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Analysis
by VulDB Data Team • 01/03/2024
The vulnerability identified as CVE-2019-15751 represents a critical unrestricted file upload flaw within the SITOS six Build v6.2.1 web application. This vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly restrict file types during the upload process. The flaw specifically affects the SCORM file upload functionality, which is commonly used for educational content delivery and learning management systems. Attackers can exploit this weakness by crafting malicious files with executable extensions that bypass the intended security controls, ultimately gaining the ability to execute arbitrary code on the target system.
The technical exploitation of this vulnerability involves the attacker uploading a specially crafted SCORM package that contains a malicious file with an executable extension such as .php, .asp, or other server-side scripting languages. When the application processes this upload without proper validation, it stores the malicious file in the web root directory, making it directly accessible via web requests. The vulnerability allows for remote code execution because the uploaded PHP code can execute operating system commands, enabling attackers to perform actions such as reading system files, establishing reverse shells, or completely compromising the server. This represents a classic path to remote code execution through file upload vulnerabilities that fall under CWE-434 Unrestricted Upload of File with Dangerous Type.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with persistent access to the compromised system. The unauthenticated nature of the attack means that any remote user can exploit this weakness without requiring valid credentials, making it particularly dangerous for publicly accessible applications. The compromise of the web root directory creates a persistent backdoor that attackers can leverage for extended periods, potentially leading to data breaches, service disruption, or further lateral movement within network environments. This vulnerability directly aligns with ATT&CK technique T1190 Exploit Public-Facing Application, which focuses on leveraging vulnerabilities in externally accessible systems to gain initial access.
Organizations affected by this vulnerability should implement immediate mitigations including restricting file upload capabilities, implementing strict file type validation, and ensuring proper file extension checks. The recommended approach involves configuring the application to reject uploads of executable files, implementing MIME type validation, and storing uploaded files outside the web root directory. Additionally, regular security updates and patch management processes should be enforced to prevent exploitation of known vulnerabilities. Network segmentation and monitoring solutions should be deployed to detect suspicious file upload activities and unauthorized access attempts. The remediation efforts must also include comprehensive security testing of file upload functionalities to identify similar weaknesses in other application components, ensuring a holistic approach to vulnerability management and risk mitigation.