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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 14 Jun 2022. Known ransomware use
QtsOperating system · Qnap

CVE-2018-19949

CRITICAL · 9.8 CVSS v3.1 Published 2020-10-28
Fix available
A fix is available. Upgrade to 4.2.6 / 4.3.3.1161 or later.
See remediation →
100/100
Remediation priority · Urgent
In the wild Ransomware Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a command injection vulnerability in QNAP QTS firmware that allows remote attackers to execute arbitrary commands on affected devices. The vulnerability is exploitable over the network without authentication, as indicated by the critical CVSS score of 9.8.

MitigationUpgrade QNAP QTS to one of the fixed versions: QTS 4.4.2.1231 (build 20200302), QTS 4.4.1.1201 (build 20200130), QTS 4.3.6.1218 (build 20200214), QTS 4.3.4.1190 (build 20200107), QTS 4.3.3.1161 (build 20200109), or QTS 4.2.6 (build 20200109).

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
QtsOperating system
Affected:< 4.2.6>= 4.3.1.0013, < 4.3.3.1161>= 4.3.4, < 4.3.4.1190>= 4.3.6, < 4.3.6.1218>= 4.4.0, < 4.4.1.1201>= 4.4.2, < 4.4.2.1231= 4.2.6

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify QNAP NAS device
    Locate QNAP devices on your network using Qfinder Pro utility, or by scanning for port 80/443 responses with QNAP-specific HTTP headers. Confirm the device is a QNAP NAS running QTS firmware.
    Affected if Device is a QNAP NAS on the network
  2. Check QTS firmware version via web interface
    Login to the QTS admin web interface (typically https://<device-ip>) and navigate to Control Panel > System > System Status. The firmware version is displayed on the main System Information page.
    Affected if Firmware version matches any of the affected ranges: < 4.2.6, = 4.2.6, >= 4.3.1.0013 to < 4.3.3.1161, >= 4.3.4 to < 4.3.4.1190, >= 4.3.6 to < 4.3.6.1218, >= 4.4.0 to < 4.4.1.1201, or >= 4.4.2 to < 4.4.2.1231
  3. Check QTS firmware version via command line
    If SSH or Telnet access is available, login and run the command: 'getsysinfo' or 'cat /etc/version'. The firmware build number and version will be displayed.
    Affected if Firmware version matches any of the affected ranges listed above
  4. Verify if the command injection endpoint is exposed
    The vulnerability affects the 'photothumbnail' CGI module. Check if the QTS web interface is externally accessible. Review firewall rules and port forwards to determine if the QTS admin portal is reachable from untrusted networks.
    Affected if QTS web interface is accessible from untrusted networks (internet or guest VLAN)

Device is affected if it is a QNAP NAS running QTS firmware version within any of the affected ranges, and the QTS web interface is network-accessible to potential attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.2.6 / 4.3.3.1161 / 4.3.4.1190 or later
Fixed in 4.2.64.3.3.11614.3.4.1190
Interim mitigation

Upgrade QNAP QTS to one of the fixed versions: QTS 4.4.2.1231 (build 20200302), QTS 4.4.1.1201 (build 20200130), QTS 4.3.6.1218 (build 20200214), QTS 4.3.4.1190 (build 20200107), QTS 4.3.3.1161 (build 20200109), or QTS 4.2.6 (build 20200109).

Recommended fix High confidence

Upgrade to QTS 4.4.2.1231 (latest stable) or the latest available version from the 4.4.x branch that includes the security patch

  1. 1. Log into QTS admin console and navigate to Control Panel > System > Firmware Update to check current QTS version.
  2. 2. Identify if your current version is vulnerable: version < 4.2.6; OR 4.3.1.0013 <= version < 4.3.3.1161; OR 4.3.4 <= version < 4.3.4.1190; OR 4.3.6 <= version < 4.3.6.1218.
  3. 3. If vulnerable, create a full backup of all data on the NAS as a precaution before firmware upgrade.
  4. 4. Download the appropriate fixed QTS version from the official QNAP download center: qnap.com.
  5. 5. In the QTS Firmware Update page, select 'Manual Firmware Update' and upload the downloaded firmware file.
  6. 6. Wait for the upgrade process to complete - do not power off the NAS during this process.
  7. 7. After reboot, verify the new version by checking Control Panel > System > Firmware Update and confirm it matches one of the fixed versions: 4.4.2.1231, 4.4.1.1201, 4.3.6.1218, 4.3.4.1190, 4.3.3.1161, or 4.2.6.
Caveat Firmware upgrades carry inherent risks - ensure data backup before proceeding; some applications or configurations may require reconfiguration post-upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Qts Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-19949 in production — separate from our analysis above.

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