CVE-2015-6568 in Wolf
Summary
by MITRE
Wolf CMS before 0.8.3.1 allows unrestricted file rename and PHP Code Execution because admin/plugin/file_manager/browse/ (aka the filemanager) does not prevent a change of a file extension to ".php" after originally using the parameter "filename" for uploading a JPEG image. Exploitation requires a registered user who has access to upload functionality.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/07/2025
The vulnerability identified as CVE-2015-6568 represents a critical security flaw in Wolf CMS versions prior to 0.8.3.1 that stems from inadequate input validation and file extension handling within the file management system. This weakness allows authenticated users with upload privileges to manipulate file extensions during the rename operation, potentially transforming legitimate image files into executable PHP scripts. The vulnerability specifically affects the admin/plugin/file_manager/browse/ endpoint which lacks proper restrictions on file extension modifications, creating an avenue for arbitrary code execution.
The technical implementation of this vulnerability exploits the file manager's failure to validate or sanitize file extensions during rename operations. When users upload files through the filename parameter, the system accepts the original extension without proper verification. An attacker can subsequently rename the uploaded JPEG file to include a .php extension, effectively converting a benign image into a potentially malicious PHP script that can be executed on the server. This flaw directly maps to CWE-434, which describes the insecure upload of executable files, and represents a classic case of insufficient input sanitization.
The operational impact of this vulnerability is severe as it provides attackers with a straightforward path to achieve remote code execution on the affected server. Since the exploit requires only a registered user account with upload permissions, it can be leveraged by both authenticated users and potentially by malicious actors who can obtain legitimate credentials. Once exploited, attackers can execute arbitrary PHP code, potentially leading to full system compromise, data exfiltration, or the installation of backdoors. This vulnerability aligns with ATT&CK technique T1505.003, which covers the use of web shells and file upload capabilities for persistence and execution.
The exploitation process involves several steps that demonstrate the vulnerability's practical nature. First, an attacker must obtain valid credentials for a user account with upload permissions. Then they upload a JPEG image file using the filename parameter, which gets stored on the server with its original extension. Finally, they rename the file through the file manager interface, changing the extension to .php, which allows the server to execute the uploaded code. This attack pattern is consistent with the ATT&CK framework's approach to file and directory manipulation techniques that enable code execution.
Mitigation strategies for this vulnerability require immediate patching of the Wolf CMS application to version 0.8.3.1 or later, which implements proper file extension validation and prevents unauthorized changes to executable file extensions. Organizations should also implement additional security measures including strict file type validation, mandatory file extension checks, and the use of whitelisting approaches for acceptable file types. The file manager should enforce restrictions that prevent any file extension changes that would result in executable code execution. Regular security audits and input validation testing should be implemented to prevent similar vulnerabilities in other components of the application stack.