CVE-2025-6776 in openvpn-cms-flask
Summary
by MITRE • 06/27/2025
A vulnerability classified as critical was found in xiaoyunjie openvpn-cms-flask up to 1.2.7. This vulnerability affects the function Upload of the file app/plugins/oss/app/controller.py of the component File Upload. The manipulation of the argument image leads to path traversal. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 1.2.8 is able to address this issue. The name of the patch is e23559b98c8ea2957f09978c29f4e512ba789eb6. It is recommended to upgrade the affected component.
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Analysis
by VulDB Data Team • 01/30/2026
This critical vulnerability exists within the xiaoyunjie openvpn-cms-flask application version 1.2.7 and earlier, specifically targeting the file upload functionality implemented in the app/plugins/oss/app/controller.py file. The flaw resides in the Upload function where improper input validation allows attackers to manipulate the image argument parameter, creating a path traversal condition that can be exploited to access arbitrary files on the server. The vulnerability's classification as critical reflects its potential for severe impact on system security and data integrity.
The technical implementation of this vulnerability stems from insufficient sanitization of user-supplied input within the file upload handler. When the application processes image uploads, it fails to properly validate or sanitize the image parameter, allowing malicious actors to inject directory traversal sequences such as ../ or ..\ that can navigate beyond the intended upload directory. This weakness enables attackers to traverse the file system and potentially access sensitive configuration files, database credentials, or other critical system resources. The vulnerability's remote exploitability means that attackers can leverage this flaw without requiring physical access to the system, making it particularly dangerous in networked environments.
The operational impact of this vulnerability extends beyond simple file access, as it can potentially lead to complete system compromise. An attacker could use the path traversal capability to read system files, execute arbitrary code, or even escalate privileges within the application environment. This vulnerability directly maps to CWE-22 Path Traversal and aligns with ATT&CK technique T1059 Command and Scripting Interpreter, as the exploitation could involve executing malicious code through the compromised upload functionality. The public disclosure of the exploit increases the likelihood of real-world attacks against unpatched systems, making immediate remediation essential.
The recommended mitigation strategy involves upgrading to version 1.2.8, which includes the patch identified by commit hash e23559b98c8ea2957f09978c29f4e512ba789eb6. This upgrade addresses the core input validation issue by implementing proper sanitization of the image parameter and enforcing strict file path restrictions during upload operations. Organizations should also consider implementing additional security controls such as input validation at multiple layers, file type restrictions, and mandatory file content verification to prevent similar vulnerabilities from occurring in other components. Security monitoring should be enhanced to detect anomalous upload patterns that might indicate exploitation attempts.