CVE-2025-14188 Overview
CVE-2025-14188 is a command injection vulnerability affecting UGREEN DH2100+ network-attached storage (NAS) devices through version 5.3.0.251125. The flaw resides in the handler_file_backup_create function processing requests to the /v1/file/backup/create endpoint of the nas_svr component. Attackers can manipulate the path argument to inject operating system commands. The vulnerability is exploitable over the network and the exploit details have been publicly disclosed. UGREEN has issued an upgrade for the affected component to remediate the issue.
Critical Impact
Authenticated remote attackers can inject arbitrary operating system commands through the backup creation API, achieving code execution in the context of the nas_svr service on UGREEN DH2100+ NAS devices.
Affected Products
- UGREEN DH2100+ NAS firmware up to and including version 5.3.0.251125
- Component: nas_svr service
- Endpoint: /v1/file/backup/create (function handler_file_backup_create)
Discovery Timeline
- 2025-12-07 - CVE-2025-14188 published to the National Vulnerability Database (NVD)
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-14188
Vulnerability Analysis
The vulnerability is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component). It allows an attacker with sufficient privileges to inject shell metacharacters into the path parameter consumed by handler_file_backup_create. When the handler constructs a backup command using this argument, the injected payload is interpreted by the underlying shell, leading to arbitrary command execution within the nas_svr process context. Because NAS services typically run with elevated privileges, successful exploitation can compromise stored data, configuration, and credentials.
Root Cause
The handler_file_backup_create function fails to neutralize shell metacharacters before passing the path argument to a downstream command interpreter. Input received via the /v1/file/backup/create endpoint is concatenated into a shell command without proper sanitization or use of safe execution APIs. This pattern of unsafe command construction is the underlying cause of [CWE-74] injection flaws.
Attack Vector
The attack vector is network-based and requires authentication with elevated privileges, according to the CVSS 4.0 vector. An attacker who has obtained credentials to the NAS management API submits a crafted HTTP request to /v1/file/backup/create with a path field containing command separators such as ;, |, &&, or backticks. The nas_svr component executes the appended commands as part of the backup workflow. Public exploitation details are referenced via VulDB submission #698833 and entry #334608. See the VulDB CTI entry #334608 for additional context.
No verified proof-of-concept code is available in trusted repositories. The vulnerability mechanism follows the standard pattern of unsanitized parameter passthrough to a shell, where a request body field such as path is concatenated into a system command invocation.
Detection Methods for CVE-2025-14188
Indicators of Compromise
- HTTP POST requests to /v1/file/backup/create containing shell metacharacters (;, |, &, backticks, $()) in the path field
- Unexpected child processes spawned by the nas_svr daemon, especially sh, bash, wget, curl, or nc
- New or modified files under backup directories that do not match scheduled backup jobs
- Outbound connections from the NAS device to unfamiliar external hosts shortly after backup API activity
Detection Strategies
- Inspect NAS access logs for requests to /v1/file/backup/create and flag path values containing non-filesystem characters
- Apply process-lineage monitoring to detect nas_svr spawning shell interpreters or networking utilities
- Compare current firmware build against the fixed UGREEN release to identify exposed devices on the network
Monitoring Recommendations
- Forward NAS application logs and authentication events to a centralized log platform for retention and correlation
- Alert on authentication attempts against the NAS API from unexpected source addresses or geographies
- Track outbound traffic from NAS devices, since these systems normally communicate with a limited set of hosts
How to Mitigate CVE-2025-14188
Immediate Actions Required
- Upgrade UGREEN DH2100+ firmware to the version released by UGREEN that addresses the nas_svr command injection
- Restrict network access to the NAS management interface using firewall rules or a management VLAN
- Rotate administrative credentials on affected devices, since exploitation requires high privileges and credentials may already be at risk
- Audit backup job configurations and review device logs for prior abuse of /v1/file/backup/create
Patch Information
UGREEN recommends upgrading the affected component. Refer to the VulDB advisory #334608 and the VulDB submission record #698833 for vendor coordination details and patch references. Apply the latest available firmware that supersedes 5.3.0.251125.
Workarounds
- Remove or block external exposure of the NAS device until the firmware update is applied
- Limit administrative API access to a small set of trusted source IP addresses
- Disable remote backup creation features if they are not operationally required
# Example: restrict access to the NAS management API to a trusted subnet
iptables -A INPUT -p tcp --dport 443 -s 10.0.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
