CVE-2021-28803

Medium

Published: 01 July 2021

Published

01 July 2021

Modified

21 November 2024

KEV Added

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Patch

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CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Score 0.0030 54.0th percentile

Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-28803 is a medium-severity Basic XSS (CWE-80) vulnerability in Qnap Q\'Center. Its CVSS base score is 5.4 (Medium).

Operationally, ranked in the top 46.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

This issue affects: QNAP Systems Inc. Q'center versions prior to 1.11.1004.

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

qnap

q\'center

≤ 1.11.1004

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.