CVE-2008-5663 in Kusaba
Summary
by MITRE
Multiple unrestricted file upload vulnerabilities in Kusaba 1.0.4 and earlier allow remote authenticated users to execute arbitrary code by uploading a file with an executable extension using (1) load_receiver.php or (2) a shipainter action to paint_save.php, then accessing the uploaded file via a direct request to this file in their user directory.
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Analysis
by VulDB Data Team • 11/07/2024
The vulnerability described in CVE-2008-5663 represents a critical security flaw in Kusaba version 1.0.4 and earlier systems that enables authenticated attackers to achieve remote code execution through unrestricted file upload capabilities. This vulnerability exists within the file handling mechanisms of the application's core components, specifically affecting two distinct upload endpoints that process user-submitted files without proper validation or sanitization. The flaw stems from insufficient input validation and access control measures that permit malicious users to bypass normal file upload restrictions and execute arbitrary code on the affected server.
The technical implementation of this vulnerability occurs through two primary attack vectors within the Kusaba application architecture. The first vector involves the load_receiver.php component which accepts file uploads without verifying file extensions or content types, while the second vector targets the shipainter functionality within paint_save.php that processes image-related uploads. Both pathways allow authenticated users to upload files with executable extensions such as .php, .asp, or .jsp, which can then be executed by the web server when accessed through direct URL requests to the user directories. This design flaw fundamentally violates secure coding practices by failing to implement proper file type validation and by not restricting file execution permissions for uploaded content.
From an operational impact perspective, this vulnerability creates a severe risk environment where authenticated attackers can escalate their privileges and gain complete control over the affected web server. The attack requires only authentication to the system, making it particularly dangerous as it can be exploited by users with legitimate access rights who may have malicious intent. Once exploited, attackers can execute arbitrary commands, access sensitive data, modify system files, and potentially establish persistent backdoors. The vulnerability also enables attackers to leverage the compromised system as a launch point for further attacks against internal networks, as the uploaded files can be accessed through direct requests to the user directories, bypassing normal application security controls. This type of vulnerability directly impacts the confidentiality, integrity, and availability of the affected systems and can result in significant data breaches and system compromise.
The vulnerability aligns with CWE-434, which specifically addresses "Unrestricted Upload of File with Dangerous Type," a well-documented weakness in software security that occurs when applications allow users to upload files without proper validation of file types or content. This weakness is further categorized under the ATT&CK framework as part of the "Initial Access" and "Execution" phases, where attackers leverage the upload capability to establish a foothold and execute malicious code. The attack scenario described in CVE-2008-5663 demonstrates how authenticated users can exploit the application's trust in legitimate file uploads to gain unauthorized execution privileges. To mitigate this vulnerability, organizations should implement strict file type validation, employ content-based file verification mechanisms, restrict file upload permissions, and ensure that uploaded files are stored outside the web root directory with appropriate access controls. Additionally, regular security audits and penetration testing should be conducted to identify similar vulnerabilities in legacy systems that may be subject to similar exploitation patterns.