What’s Vulnerable › Vulnerabilities

CVE-2021-28807: Post-Authentication Reflected XSS Vulnerability in Q'center

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-06-03 · updated 2026-06-17
• Weakness: CWE-79

Description

A post-authentication reflected XSS vulnerability has been reported to affect QNAP NAS running Q’center. If exploited, this vulnerability allows remote attackers to inject malicious code. QNAP have already fixed this vulnerability in the following versions of Q’center: QTS 4.5.3: Q’center v1.12.1012 and later QTS 4.3.6: Q’center v1.10.1004 and later QTS 4.3.3: Q’center v1.10.1004 and later QuTS hero h4.5.2: Q’center v1.12.1012 and later QuTScloud c4.5.4: Q’center v1.12.1012 and later

Affected products

• QNAP Q'Center: before 1.12.1012; before 1.10.1004 — fixed in 1.10.1004, 1.12.1012

How to fix

Upgrade to a fixed version: QNAP Q'Center 1.10.1004, 1.12.1012. Check the vendor advisory for mitigations.

References

• https://www.qnap.com/zh-tw/security-advisory/qsa-21-20
• https://www.shielder.it/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/
• https://www.shielder.it/advisories/qnap-qcenter-virtual-stored-xss/
• https://www.qnap.com/zh-tw/security-advisory/qsa-21-20
• https://www.shielder.it/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/
• https://www.shielder.it/advisories/qnap-qcenter-virtual-stored-xss/

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