CVE-2011-4828 in V-CMS
Summary
by MITRE
Unrestricted file upload vulnerability in includes/inline_image_upload.php in AutoSec Tools V-CMS 1.0 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 temp/.
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Analysis
by VulDB Data Team • 01/05/2025
The vulnerability identified as CVE-2011-4828 represents a critical unrestricted file upload flaw within the AutoSec Tools V-CMS 1.0 content management system. This vulnerability exists in the includes/inline_image_upload.php component which fails to properly validate file extensions and content types during the upload process. The flaw allows remote attackers to bypass security restrictions and upload malicious files with executable extensions such as .php, .asp, or .jsp directly to the server's temporary directory. The vulnerability stems from inadequate input validation and sanitization mechanisms that should have prevented the upload of files with potentially dangerous extensions. According to CWE-434, this represents a weakness where applications allow file uploads without proper restrictions on file types, creating an avenue for attackers to execute arbitrary code on the target system.
The technical exploitation of this vulnerability requires minimal prerequisites and can be accomplished through a straightforward attack vector. An attacker simply needs to craft a malicious file with an executable extension and upload it through the vulnerable inline image upload functionality. Once the file is successfully uploaded to the temp/ directory, the attacker can execute the payload by making a direct HTTP request to the file's location. This direct access method bypasses normal web application security controls and allows for immediate code execution with the privileges of the web server process. The vulnerability is particularly dangerous because it leverages a common web application functionality while exploiting a fundamental security flaw in file handling processes. The attack can be classified under ATT&CK technique T1190 for exploiting vulnerabilities in web applications, specifically targeting the execution of malicious code through file upload mechanisms.
The operational impact of this vulnerability extends beyond simple code execution to encompass full system compromise potential. Successful exploitation enables attackers to establish persistent access, deploy additional malicious tools, and potentially escalate privileges within the compromised environment. The vulnerability affects the confidentiality, integrity, and availability of the web application and underlying infrastructure. Organizations using AutoSec Tools V-CMS 1.0 become vulnerable to various attack scenarios including web shell deployment, data exfiltration, and lateral movement within network environments. The temporary directory location provides attackers with a predictable path for executing uploaded malicious files, making the attack surface more accessible. This vulnerability represents a critical risk for web applications that handle user-uploaded content without proper security controls, as it allows for immediate arbitrary code execution with potentially elevated privileges.
Mitigation strategies for CVE-2011-4828 must address both immediate remediation and long-term architectural improvements. The most effective immediate solution involves implementing strict file type validation that rejects uploads of executable files regardless of their extensions or content. Organizations should employ multiple validation layers including MIME type checking, file extension filtering, and content analysis to prevent malicious file uploads. The temporary directory should be secured by removing execute permissions and implementing proper access controls to prevent direct file access. Additionally, uploaded files should be stored in non-executable directories and renamed to prevent predictable paths. According to security best practices, all file upload functionality should be reviewed and hardened through proper input validation, output encoding, and secure file handling procedures. Regular security assessments and vulnerability scanning should be implemented to identify similar weaknesses in other application components, while implementing proper logging and monitoring to detect suspicious file upload activities. The remediation process should also include updating the CMS to a patched version if available, or implementing compensating controls such as web application firewalls and secure coding practices to prevent similar vulnerabilities from being introduced in future development cycles.