How severe is CVE-2021-38674?

CVE-2021-38674 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-38674 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38674?

CVE-2021-38674 primarily affects Qnap Qts. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-38674?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-38674 published?

CVE-2021-38674 was published on 2022-01-07 and last updated on 2026-06-17.

CVE-2021-38674

CVE-2021-38674 is a medium-severity vulnerability in Qnap Qts with a CVSS 3.x base score of 4.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
CVSS v2: 4.3
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Qnap Qts
Published: 2022-01-07
Last modified: 2026-06-17

Description

A cross-site scripting (XSS) vulnerability has been reported to affect QTS, QuTS hero and QuTScloud. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of QTS, QuTS hero and QuTScloud: QuTS hero h4.5.4.1771 build 20210825 and later QTS 4.5.4.1787 build 20210910 and later QuTScloud c4.5.7.1864 and later

Frequently asked questions

What is CVE-2021-38674?: A cross-site scripting (XSS) vulnerability has been reported to affect QTS, QuTS hero and QuTScloud. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of QTS, QuTS hero and QuTScloud: QuTS hero h4.5.4.1771 build 20210825 and later QTS 4.5.4.1787 build 20210910 and later QuTScloud c4.5.7.1864 and later
How severe is CVE-2021-38674?: CVE-2021-38674 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-38674 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38674?: CVE-2021-38674 primarily affects Qnap Qts. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-38674?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-38674 published?: CVE-2021-38674 was published on 2022-01-07 and last updated on 2026-06-17.

References

https://www.qnap.com/en/security-advisory/qsa-21-63

Affected products (3)

cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:*:*:*:*:*:*:*:*
cpe:2.3:o:qnap:qutscloud:*:*:*:*:*:*:*:*

More vulnerabilities in Qnap Qts

CVE-2024-32766 — Critical (CVSS 10.0): An OS command injection vulnerability has been reported to affect several QNAP operating system versions. If exploited,…
CVE-2017-7876 — Critical (CVSS 10.0): This command injection vulnerability in QTS allows attackers to run arbitrary commands in the compromised application.…
CVE-2025-66276 — Critical (CVSS 9.8): QuTS hero is not affected. We have already fixed the vulnerability in the following version: QTS 5.2.7.3256 build…
CVE-2025-66277 — Critical (CVSS 9.8): A link following vulnerability has been reported to affect several QNAP operating system versions. The remote attackers…
CVE-2025-62849 — Critical (CVSS 9.8): An SQL injection vulnerability has been reported to affect several QNAP operating system versions. The remote attackers…
CVE-2025-59385 — Critical (CVSS 9.8): An authentication bypass by spoofing vulnerability has been reported to affect several QNAP operating system versions.…

All CVEs affecting Qnap Qts →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →