CVE-2014-8997 in Digi Online Examination System
Summary
by MITRE
Unrestricted file upload vulnerability in the Photo functionality in DigitalVidhya Digi Online Examination System 2.0 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 assets/uploads/images/.
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Analysis
by VulDB Data Team • 01/20/2025
The CVE-2014-8997 vulnerability represents a critical security flaw in the DigitalVidhya Digi Online Examination System version 2.0, specifically within its photo upload functionality. This vulnerability falls under the category of unrestricted file upload, a common yet dangerous weakness that allows attackers to bypass normal file validation mechanisms and upload malicious files to the target system. The vulnerability is particularly concerning because it enables remote code execution, which can lead to complete system compromise and unauthorized access to sensitive data. The attack vector is straightforward yet effective, as it leverages the system's failure to properly validate file extensions and content, allowing malicious actors to upload executable files that can be executed directly through the web server.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the photo upload component of the examination system. When users upload images through the designated functionality, the system fails to properly verify the file type or content, instead accepting any file with an executable extension such as .php, .asp, .jsp, or .exe. The uploaded files are stored in the assets/uploads/images/ directory, making them directly accessible via web requests. This design flaw creates a pathway for attackers to upload malicious scripts that can be executed on the server, effectively turning the legitimate photo upload feature into a weapon for code execution. The vulnerability is classified as CWE-434, which specifically addresses the issue of unrestricted upload of file with dangerous type, and it directly maps to ATT&CK technique T1190, which covers the exploitation of vulnerabilities in web applications.
The operational impact of this vulnerability is severe and far-reaching, as it provides attackers with a persistent means of gaining unauthorized access to the examination system's underlying infrastructure. Once an attacker successfully uploads a malicious file, they can execute arbitrary code with the privileges of the web server process, potentially leading to data theft, system compromise, or the establishment of backdoors for continued access. The vulnerability affects the confidentiality, integrity, and availability of the system, as attackers can modify or delete examination data, inject malicious code into the platform, or even use the compromised system as a launching point for attacks on other network resources. The exposure of examination data, including student information, test results, and sensitive academic records, poses significant risks to educational institutions and their stakeholders. The vulnerability also undermines the trust in the examination system's security and can lead to regulatory compliance issues, especially in environments where data protection and privacy are paramount.
Mitigation strategies for CVE-2014-8997 require immediate implementation of multiple defensive layers to prevent unauthorized file uploads and execution. Organizations should implement strict file type validation mechanisms that reject executable files regardless of their extension, and should also validate file content using proper file signature checking rather than relying solely on extension-based validation. The system should employ a whitelist approach for acceptable file types, rejecting all files that do not match predetermined safe formats such as .jpg, .png, or .gif. Additionally, uploaded files should be stored outside the web root directory, and proper access controls should be implemented to prevent direct execution of uploaded files. The web server configuration should be adjusted to prevent execution of scripts in upload directories, and the system should implement proper authentication and authorization controls to limit access to the upload functionality. Regular security audits and penetration testing should be conducted to identify and remediate similar vulnerabilities, while keeping the system updated with the latest security patches and following secure coding practices that prevent similar issues from occurring in future development cycles.