CVE DatabaseCVE-2018-19949

Updated 2026-10-02한국어 권고문 →

CVE-2018-199499.8/CRITICALCISA KEVCWE-20CWE-77CWE-78CWE-77

QNAP QTS Remote Command Injection Vulnerability (CVE-2018-19949) Security Advisory

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Affected Vendors

qnap

Affected Components

qts

Published Date

2020-10-28

CVSS v3.1

9.8

CRITICAL

EPSS (30d)

30.2%

FIRST.org

CISA KEV

Exploited

NVD Source ↗

Executive & SecOps Summary

SECOPS ASSESSMENT

Affected Scope

QNAP QTS versions prior to 4.4.2.1231 Build 20200302, 4.4.1.1201 Build 20200130, 4.3.6.1218 Build 20200214, 4.3.4.1190 Build 20200107, 4.3.3.1161 Build 20200109, and 4.2.6 Build 20200109

Impact

Unauthenticated remote attackers can execute arbitrary OS commands with root privileges on the target NAS device, leading to complete system compromise

Mitigation

Immediately upgrade QTS to the latest patched firmware version and restrict external internet access to the NAS management interface

Affected Products & Version Scope

QNAP QTS versions prior to 4.4.2.1231 Build 20200302, 4.4.1.1201 Build 20200130, 4.3.6.1218 Build 20200214, 4.3.4.1190 Build 20200107, 4.3.3.1161 Build 20200109, and 4.2.6 Build 20200109

Remediation & Live Workaround Commands

PATCH & WORKAROUND

1. Official Patch & Version Upgrade Commands

Log in to the QTS web interface to perform a live update, or use the SSH terminal to trigger a firmware update to the latest secure release.

bash

# Check and install the latest secure QTS firmware via CLI
# Note: This action may require a system reboot.
/sbin/update_firmware --check
/sbin/update_firmware --download_and_install

2. Temporary Workaround & Hardening Configuration

If immediate patching is not feasible, restrict access to the QTS management ports (default 8080, 443) using firewall rules to allow only trusted administrative IPs.

bash

# Restrict QTS web administration access to a trusted admin IP (e.g., 192.168.1.100)
iptables -A INPUT -p tcp -s 192.168.1.100 --dport 8080 -j ACCEPT
iptables -A INPUT -p tcp -s 192.168.1.100 --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP

3. Log Audit & IoC Verification Commands

Verify the current QTS version and inspect web server logs for potential command injection attempts.

bash

# Retrieve current QTS version and build details
getcfg System Version
getcfg System 'Build Number'

# Scan web server access logs for common command injection patterns
grep -Ei '(\;|\`|\||\&|wget|curl|sh\s)' /mnt/ext/opt/apache/logs/access_log

Interactive SecOps Remediation Checklist

0/4 (0%)

Recommended Security Control & Mitigation Partner

NordLayer / Zero-Trust Network Access

As this vulnerability is actively exploited in the wild (CISA KEV), immediately verify your QTS version and apply the latest security updates.

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Technical Root Cause & Exploitation Mechanics

1. Vulnerability Overview & Root Cause

This vulnerability (CVE-2018-19949) is a critical command injection flaw in QNAP QTS, the operating system for QNAP NAS devices. The root cause lies in improper input validation (CWE-20, CWE-78) where user-supplied input is passed directly to system shell commands without adequate sanitization. This allows remote attackers to inject shell metacharacters and execute arbitrary system commands under the context of the web server process.

2. Exploitation Mechanics & Attack Scenario

An unauthenticated attacker can exploit this vulnerability by sending specially crafted HTTP requests containing malicious payloads to vulnerable endpoints on the QTS web interface. By embedding shell metacharacters (such as ';', '`', or '&') into input parameters, the attacker forces the underlying operating system to execute appended commands. Since this vulnerability is actively exploited in the wild and listed in the CISA KEV catalog, automated scanning and exploitation tools are highly likely to target exposed devices.

3. Infrastructure & Business Impact

Successful exploitation allows complete control over the QNAP NAS device. Attackers can access, modify, or delete sensitive stored data, deploy ransomware, or use the compromised NAS as a pivot point to launch further attacks inside the internal network. This poses severe risks to data confidentiality, integrity, and overall business continuity.

Official Vendor Advisories & References

NVD Original English Description

If exploited, this command injection vulnerability could allow remote attackers to run arbitrary commands. QNAP has already fixed the issue in the following QTS versions. QTS 4.4.2.1231 on build 20200302; QTS 4.4.1.1201 on build 20200130; QTS 4.3.6.1218 on build 20200214; QTS 4.3.4.1190 on build 20200107; QTS 4.3.3.1161 on build 20200109; QTS 4.2.6 on build 20200109.

https://www.qnap.com/zh-tw/security-advisory/qsa-20-01

Source: security@qnapsecurity.com.tw · Vendor Advisory

https://www.qnap.com/zh-tw/security-advisory/qsa-20-01

Source: af854a3a-2127-422b-91ae-364da2661108 · Vendor Advisory

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-19949

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 · US Government Resource

Frequently Asked SecOps Questions (CVE-2018-19949)

FAQ

Q1. How critical is CVE-2018-19949 and is it actively exploited in the wild?

CVE-2018-19949 is rated CVSS 9.8 (CRITICAL) with a 30-day EPSS exploitation probability of 30.2%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.

Q2. Which vendors and products are affected by CVE-2018-19949?

Primary impacted vendors include qnap across qts. Scope summary: QNAP QTS versions prior to 4.4.2.1231 Build 20200302, 4.4.1.1201 Build 20200130, 4.3.6.1218 Build 20200214, 4.3.4.1190 Build 20200107, 4.3.3.1161 Build 20200109, and 4.2.6 Build 20200109

Q3. What temporary mitigations or workarounds exist for CVE-2018-19949 before patching?

[Mitigation] Immediately upgrade QTS to the latest patched firmware version and restrict external internet access to the NAS management interface Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.

SECOPS WORKBENCH INTEGRATION