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NVD / CVE Program· CNA qnap

CVE-2018-19943: If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code.

MediumCVSS 5.4 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: Plan (action score 58/100)

  • CISA has confirmed exploitation in the wild (May 24, 2022); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Jun 14, 2022.
  • Probability of exploitation in the next 30 days: 22.6% (FIRST EPSS); higher than 97.7% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.
  • Severity is disputed: the assigning authority (CNA) scores it 8.0, NVD 5.4.

Add it to your regular patch cycle. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code. QNAP has already fixed these issues in the following QTS versions. QTS 4.4.2.1270 build 20200410 and later QTS 4.4.1.1261 build 20200330 and later QTS 4.3.6.1263 build 20200330 and later QTS 4.3.4.1282 build 20200408 and later QTS 4.3.3.1252 build 20200409 and later QTS 4.2.6 build 20200421 and later

Published
Oct 28, 2020
Updated
Aug 13, 2026
EPSS
22.6% · 97th percentile

Report tools

JSON

Action score

58

Plan

Add it to your regular patch cycle.

CVSS
21 / 40 · 5.4 / 10
CISA KEV
30 / 30 · Listed
EPSS
7 / 30 · 22.6%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.4
CNA · qnap
8.0
2.6 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on May 24, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jun 14, 2022.

Known to be used in ransomware campaigns.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2018-19943

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
qnapqts

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Versions reported by the vendor

Affected version ranges reported by the assigning authority (qnap). Independent of NVD's CPE analysis and usually ahead of it.

  • QNAP Systems Inc. QTS

    • unspecified and later · before 4.4.2.1270affected
    • unspecified and later · before 4.4.1.1261affected
    • unspecified and later · before 4.3.6.1263affected
    • unspecified and later · before 4.3.4.1282affected
    • unspecified and later · before 4.3.3.1252affected
    • unspecified and later · before 4.2.6affected
Affected versions · NVD (7)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • qnap qtsbefore 4.2.6
  • qnap qts4.3.1.0013 and later · before 4.3.3.1252
  • qnap qts4.3.4 and later · before 4.3.4.1282
  • qnap qts4.3.6 and later · before 4.3.6.1263
  • qnap qts4.4.0 and later · before 4.4.1.1261
  • qnap qts4.4.2 and later · before 4.4.2.1270
  • qnap qts4.2.6

Same product

qnap: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-2509Command Injection Vulnerability in QTS and QuTS heroKEV
    79This week
  • CVE-2018-19949If exploited, this command injection vulnerability could allow remote attackers to run arbitrary commands.KEV
    78This week
  • CVE-2019-7193This improper input validation vulnerability allows remote attackers to inject arbitrary code to the system.KEV
    73This week

Published before and after this one in the same product

  • ← EarlierCVE-2019-7197Dec 4, 2019 · A stored cross-site scripting (XSS) vulnerability has been reported to affect multiple versions of QTS.
    19Monitor
  • ← EarlierCVE-2019-7183Dec 5, 2019 · This improper link resolution vulnerability allows remote attackers to access system files.
    39Monitor
  • Later →CVE-2018-19953Oct 28, 2020 · If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code.KEV
    63This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. CISA KEV+572 d
  3. TodayNov 14, 2026+2207 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Not on record for this CVE: patch commit or PR link · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

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

nvd-primary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

The bug in code

The whole CWE-79 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records