CVE-2021-28807

Name: CVE-2021-28807
Creator: NVD / NIST
Published: 2021-06-03T03:15:08.533+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 1.38%

Last modified Jun 17, 2026

CVE-2021-28807 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 1.38% chance of exploitation in the next 30 days.

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

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

1.38%

68.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Qnap	Q\'Center	< 1.12.1012
Qnap	Q\'Center	< 1.10.1004

References

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

Timeline

Published: Jun 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-28807?

How severe is CVE-2021-28807?

CVE-2021-28807 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 1.38% probability of exploitation in the next 30 days.

How do I fix CVE-2021-28807?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-28807?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST