CVE-2008-7088 in PhotoPost vBGallery
Summary
by MITRE
Unrestricted file upload vulnerability in upload.php in PhotoPost vBGallery 2.4.2 allows remote authenticated users to execute arbitrary code by uploading a file with an executable extension followed by a safe extension, then accessing it via a direct request to the file in a certain path. NOTE: this may be the same vulnerability as CVE-2008-0251, but this is not clear due to lack of details from the vendor.
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Analysis
by VulDB Data Team • 11/02/2024
The vulnerability described in CVE-2008-7088 represents a critical unrestricted file upload flaw within the PhotoPost vBGallery 2.4.2 web application. This vulnerability exists in the upload.php script and affects authenticated users who can successfully navigate the application's authentication mechanisms. The flaw stems from inadequate input validation and file extension checking within the file upload process, creating a pathway for malicious actors to bypass security controls and deploy malicious payloads. The vulnerability operates under the premise that the application fails to properly validate file types based on their content rather than relying solely on extension-based checks, which is a fundamental weakness in web application security design.
The technical exploitation of this vulnerability involves a sophisticated approach where attackers can upload files with executable extensions such as .php, .asp, or .jsp followed by seemingly benign extensions like .jpg or .gif. This technique leverages the application's failure to properly sanitize file names and validate file content, allowing the malicious payload to be stored on the server with a disguise that makes it appear as a legitimate media file. When the uploaded file is accessed through a direct HTTP request to the file path, the web server executes the malicious code rather than serving it as a static image or document. This method of exploitation directly violates the principle of least privilege and demonstrates a complete breakdown in the application's security controls.
From an operational impact perspective, this vulnerability creates a severe risk for organizations using PhotoPost vBGallery 2.4.2 as it allows authenticated attackers to gain remote code execution capabilities on the affected web server. The implications extend beyond simple data theft to include full system compromise, allowing attackers to establish persistent backdoors, exfiltrate sensitive data, or use the compromised server as a launch point for further attacks within the network. The vulnerability affects the confidentiality, integrity, and availability of the web application and underlying infrastructure, potentially leading to complete system compromise. Security professionals should note that this vulnerability aligns with CWE-434, which specifically addresses insecure file upload vulnerabilities where applications accept files without proper validation.
The exploitation of this vulnerability directly maps to several tactics outlined in the MITRE ATT&CK framework, particularly focusing on initial access through web application attacks and privilege escalation via code execution. Attackers can leverage this vulnerability to establish a foothold within the network, potentially leading to lateral movement and further compromise of adjacent systems. The persistence aspect of this vulnerability is particularly concerning as the uploaded malicious files can remain undetected for extended periods, allowing attackers to maintain control over the compromised system. Security teams should consider implementing network monitoring solutions to detect unusual file upload patterns and direct access requests to potentially malicious files.
Organizations should implement multiple layers of defense to mitigate this vulnerability, including implementing strict file type validation, using randomized file names to prevent predictable paths, and deploying web application firewalls to monitor and block suspicious upload activities. The fix requires modifying the upload.php script to implement comprehensive file validation that checks both file extensions and actual file content, using techniques such as MIME type checking and file signature validation. Additionally, proper file permissions and upload directory restrictions should be enforced to prevent execution of uploaded files in web-accessible locations. This vulnerability underscores the importance of defense in depth strategies and proper input validation as recommended by OWASP Top Ten and other security frameworks, demonstrating how a single validation flaw can lead to complete system compromise.