Security Advisory for Vulnerabilities in QTS
Cross-site Scripting (XSS) vulnerability in NAS devices of QNAP Systems Inc. QTS allows attackers to inject javascript. This issue affects: QNAP Systems Inc. QTS version 4.2.6 and prior versions on build 20180711; version 4.3.3 and prior versions on build 20180725; version 4.3.4 and prior versions on build 20180710.
- Published
- Nov 27, 2018
- Updated
- Jun 16, 2026
- EPSS
- 0.8% · 53th percentile
- CWE
- CWE-79
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.8%
CNA vs NVD score
- NVD
- —
- CNA · qnap
- 5.5
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| qnap | qts | cpe:2.3:o:qnap:qts |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- qnap qts4.2.6
- qnap qts4.3.3
- qnap qts4.3.4
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 · up to and including 4.3.4affected
- unspecified and later · up to and including 4.2.6affected
- unspecified and later · up to and including 4.3.3affected
Same product
qnap: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-2509Command Injection Vulnerability in QTS and QuTS heroKEV79This week
- CVE-2018-19949If exploited, this command injection vulnerability could allow remote attackers to run arbitrary commands.KEV78This week
- CVE-2019-7193This improper input validation vulnerability allows remote attackers to inject arbitrary code to the system.KEV73This week
- CVE-2018-19953If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code.KEV63This week
- CVE-2023-47218QTS, QuTS hero, QuTScloud60This week
- CVE-2017-6360QNAP QTS before 4.2.4 Build 20170313 allows attackers to gain administrator privileges and obtain sensitive information via unspecified vect59Plan
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
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
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
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- Low
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:U/C:L/I:L/A:L
nvd-secondary
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 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
commentEl.innerHTML = comment.body;Fixed
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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.