CVE-2017-17560 in MyCloud PR4100
Summary
by MITRE
An issue was discovered on Western Digital MyCloud PR4100 2.30.172 devices. The web administration component, /web/jquery/uploader/multi_uploadify.php, provides multipart upload functionality that is accessible without authentication and can be used to place a file anywhere on the device's file system. This allows an attacker the ability to upload a PHP shell onto the device and obtain arbitrary code execution as root.
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Analysis
by VulDB Data Team • 08/10/2025
The vulnerability identified as CVE-2017-17560 represents a critical authentication bypass flaw within the Western Digital MyCloud PR4100 storage device firmware version 2.30.172. This issue resides in the web administration component located at /web/jquery/uploader/multi_uploadify.php, which exposes a multipart file upload functionality that operates without requiring any form of authentication. The flaw stems from inadequate access controls and improper input validation within the device's web interface, creating a pathway for unauthenticated attackers to exploit the system's file upload capabilities.
The technical implementation of this vulnerability allows attackers to bypass the device's authentication mechanisms entirely, enabling them to upload malicious files directly to any location within the device's file system. This unrestricted file placement capability is particularly dangerous because it operates at the system level, granting attackers the ability to place PHP shell scripts in directories that are executed with root privileges. The multi_uploadify.php endpoint specifically lacks proper authorization checks, meaning any remote attacker can access this functionality without presenting valid credentials or authentication tokens.
The operational impact of this vulnerability is severe and encompasses complete system compromise. An attacker who successfully exploits this flaw can achieve arbitrary code execution with root privileges, effectively gaining full control over the device. This level of access enables malicious actors to install persistent backdoors, modify system configurations, exfiltrate stored data, or use the device as a pivot point for attacking other systems within the network. The vulnerability essentially transforms the storage device from a legitimate network resource into a potential command and control server or a launching point for further attacks.
The flaw aligns with CWE-285, which addresses insufficient authorization issues, and represents a classic example of insecure direct object references that allow attackers to manipulate file paths and upload locations. From an adversarial perspective, this vulnerability maps to multiple ATT&CK techniques including T1059 for command and scripting interpreter usage, T1078 for valid accounts, and T1566 for phishing with malicious attachments. The attack surface is particularly concerning given that the device is designed for network storage and likely contains sensitive personal or corporate data, making it a valuable target for cybercriminals seeking persistent access to network resources.
Mitigation strategies should focus on immediate firmware updates from Western Digital to address the authentication bypass and file upload restrictions. Network segmentation and firewall rules should be implemented to restrict access to the device's web administration interfaces, while monitoring systems should be deployed to detect unusual file upload patterns or unauthorized access attempts. Additionally, regular security audits of network storage devices should be conducted to identify similar vulnerabilities, and organizations should implement principle of least privilege access controls for all administrative interfaces. The vulnerability highlights the critical importance of secure coding practices and proper input validation in web applications, particularly those handling file upload functionality.