CVE-2015-3203 in h5ai
Summary
by MITRE
Unrestricted file upload vulnerability in h5ai before 0.25.0 allows remote attackers to execute arbitrary code by uploading a file with an executable extension, then accessing it via a direct request to the file in the directory specified by the href parameter.
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Analysis
by VulDB Data Team • 01/22/2025
The vulnerability identified as CVE-2015-3203 represents a critical unrestricted file upload flaw in h5ai version 0.25.0 and earlier, presenting significant security risks to web applications utilizing this file manager. This issue stems from inadequate input validation and sanitization mechanisms that fail to properly restrict file types allowed for upload operations. The vulnerability specifically affects the directory listing and file management capabilities of h5ai, a popular web-based file manager that provides directory browsing and file operations through a web interface. Attackers can exploit this weakness by uploading malicious files with executable extensions such as .php, .asp, .jsp, or other server-side script extensions, thereby gaining the ability to execute arbitrary code on the target system.
The technical exploitation of CVE-2015-3203 involves leveraging the web application's lack of proper file extension validation and content type checking. When users upload files through the h5ai interface, the system does not adequately verify that uploaded files conform to expected file types or contain malicious code. This vulnerability falls under CWE-434, which describes "Unrestricted Upload of File with Dangerous Type," a well-documented weakness in software security that has been consistently flagged in various security assessments and penetration testing scenarios. The flaw allows attackers to bypass normal security controls and upload potentially harmful files that can be executed directly by the web server. The attack vector becomes particularly dangerous when combined with the directory traversal capabilities of h5ai, as attackers can directly access uploaded files through the directory structure, eliminating the need for additional exploitation steps.
The operational impact of this vulnerability extends beyond simple code execution, as it can lead to complete system compromise and unauthorized access to sensitive data. Once an attacker successfully uploads a malicious file, they can leverage the direct request functionality to execute the payload, potentially gaining shell access, escalating privileges, or deploying additional malware. The vulnerability is particularly concerning in environments where h5ai is used for shared file management or public file sharing, as it provides attackers with a straightforward path to compromise the underlying web server infrastructure. According to ATT&CK framework techniques, this vulnerability maps to T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1505.003 for "Server Software Component: Web Shell," indicating the potential for persistent access and post-compromise activities. The vulnerability affects not just the immediate web application but can also provide attackers with a foothold for lateral movement within network environments, especially when the web server hosts other sensitive applications or databases.
Organizations using affected versions of h5ai should implement immediate mitigations to address this vulnerability, including updating to version 0.25.0 or later where the issue has been resolved through proper input validation and file type restriction mechanisms. Additional protective measures include implementing strict file extension filtering, disabling executable file uploads, configuring web server security modules to prevent execution of uploaded files, and implementing proper access controls and monitoring for suspicious file upload activities. The resolution of this vulnerability demonstrates the importance of proper input validation and the principle of least privilege in web application security, where file upload functionality should never be treated as a trusted operation without proper sanitization and validation checks. Security teams should also conduct comprehensive assessments of all file management and upload capabilities within their web applications to identify similar vulnerabilities that may exist in other software components.