CVE-2021-28807
Post-Authentication Reflected XSS Vulnerability in Q'center
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
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Post-Authentication Reflected XSS Vulnerability in Q'center
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
- Record
CVE-2021-28807- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-15463
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
- Record
EUVD-2021-15463- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4g4m-4574-88xm No score
A post-authentication reflected XSS vulnerability has been reported to affect QNAP NAS running Q...
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
- Record
GHSA-4g4m-4574-88xm- Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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
- Record
CVE-2021-28807- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-28807 is a high vulnerability (CVSS 7.7) in Qnap Systems Inc. Q’center, published June 3, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.38%, the 72nd percentile. No source names a fixed version.