CVE-2026-15539 in Online Book Store System
Summary
by MITRE • 07/13/2026
A security vulnerability has been detected in SourceCodester Online Book Store System 1.0. Impacted is an unknown function of the file /admin/index.php?page=books of the component Book Image Upload Feature. Such manipulation leads to unrestricted upload. The attack may be performed from remote. The exploit has been disclosed publicly and may be used.
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Analysis
by VulDB Data Team • 07/13/2026
This vulnerability represents a critical security flaw in the SourceCodester Online Book Store System version 1.0, specifically within the administrative interface's book image upload functionality. The issue manifests in the file /admin/index.php?page=books where an unrestricted file upload vulnerability exists, allowing attackers to bypass normal file validation mechanisms and upload malicious files to the server. This type of vulnerability falls under CWE-434, which specifically addresses the insecure upload of executable files, and represents a significant weakening of the application's security posture. The vulnerability is particularly dangerous because it operates through an administrative component, providing attackers with elevated privileges and potential access to sensitive system resources.
The technical implementation flaw stems from inadequate input validation and sanitization within the file upload process. When administrators or authenticated users attempt to upload book images through the interface, the application fails to properly verify file types, extensions, or content signatures before storing files on the server. This allows attackers to submit malicious files such as php shells, webshells, or other executable code that can be executed within the web server context. The vulnerability is remotely exploitable, meaning an attacker does not require physical access to the system but can leverage network-based attacks through the web interface to gain unauthorized code execution capabilities.
The operational impact of this vulnerability extends far beyond simple data theft or modification. An attacker who successfully exploits this unrestricted upload vulnerability gains the ability to execute arbitrary code on the target server, potentially leading to complete system compromise. This could result in data exfiltration, service disruption, lateral movement within the network, and establishment of persistent backdoors. The attack vector is particularly concerning because it leverages legitimate administrative functionality, making detection more difficult through traditional security monitoring approaches. The public disclosure of exploit details further amplifies the risk as malicious actors can immediately implement attacks without requiring advanced technical knowledge or reconnaissance efforts.
Mitigation strategies must address both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities. Organizations should implement strict file type validation using whitelisting approaches rather than blacklisting, enforce proper content verification through file signature checks, and ensure uploaded files are stored outside the web root directory with appropriate access controls. The principle of least privilege should be applied by restricting upload permissions to only necessary administrative users and implementing separate execution contexts for uploaded files. Security controls such as web application firewalls, input validation layers, and regular security scanning should be deployed to detect and prevent exploitation attempts. Additionally, implementing proper logging and monitoring around file upload activities can help identify suspicious behavior patterns that may indicate exploitation attempts. This vulnerability demonstrates the critical importance of proper secure coding practices and adherence to security standards including those outlined in the OWASP Top Ten and NIST cybersecurity frameworks, particularly focusing on input validation and access control mechanisms.