CVE-2011-5005 in QuiXplorer
Summary
by MITRE
Unrestricted file upload vulnerability in QuiXplorer 2.3 and earlier allows remote attackers to execute arbitrary code by uploading a file with an executable extension using the upload action to index.php, then accessing it via a direct request to the file in an unspecified directory.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability identified as CVE-2011-5005 represents a critical security flaw in QuiXplorer version 2.3 and earlier, specifically targeting the file upload functionality within the application's index.php script. This issue stems from inadequate input validation and sanitization mechanisms that fail to properly restrict file types during the upload process, creating an avenue for remote attackers to bypass security controls and execute malicious code on the affected system. The vulnerability is classified under CWE-434 as an Unrestricted Upload of File with Dangerous Type, which directly relates to the absence of proper file type validation that would normally prevent execution of potentially harmful files.
The technical exploitation of this vulnerability involves a multi-stage attack process where malicious actors first upload a file with an executable extension through the vulnerable upload functionality in index.php. The application's failure to implement proper file extension validation and content inspection allows attackers to bypass security checks and successfully store malicious files on the server. Once uploaded, these files can be accessed directly through a web request to the file location in an unspecified directory, enabling remote code execution capabilities. This weakness creates a persistent threat vector that can be leveraged for various malicious activities including but not limited to web shell deployment, privilege escalation, and data exfiltration.
The operational impact of CVE-2011-5005 extends beyond simple code execution, as it fundamentally compromises the integrity and confidentiality of the affected system. Attackers can leverage this vulnerability to establish persistent access, deploy additional malware, or use the compromised system as a launching point for further attacks within the network infrastructure. The vulnerability's classification under the ATT&CK framework would align with techniques such as T1190 for Exploit Public-Facing Application and T1059 for Command and Scripting Interpreter, demonstrating how this flaw enables attackers to maintain long-term access and execute commands on the compromised host. The unrestricted nature of the file upload capability means that attackers can upload various file types including php, aspx, or other executable scripts that can be executed by the web server.
Organizations utilizing QuiXplorer versions 2.3 or earlier face significant risk from this vulnerability, particularly in environments where the application is exposed to untrusted users or external networks. The attack surface is expanded by the lack of proper file validation, which means that even if users have legitimate access to the system, they could potentially exploit this weakness to gain unauthorized access. Security best practices recommend immediate remediation through patching to version 2.4 or later, which includes proper file type validation and content inspection mechanisms. Additional mitigations should include implementing strict file type restrictions, deploying web application firewalls, and conducting regular security assessments to identify similar vulnerabilities in other applications. The vulnerability also highlights the importance of input validation and the principle of least privilege in web application security, as proper implementation of these controls could have prevented the exploitation of this weakness.