CVE-2021-28807 json
Post-Authentication Reflected XSS Vulnerability in Q'center
published 5y ago modified 4mo ago also EUVD-2021-15463
- cvss
- 7.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.4%
- EPSS 1.4% chance of exploitation in 30 days, percentile 72%
- public exploits
- 0
- none known
Summary
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
Patch / fix
- QNAP Systems Inc. Q’center v1.10.1004, v1.12.1012
Is CVE-2021-28807 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
1.38% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- shielder.it https://www.shielder.it/advisories/qnap-qcenter-virtual-stored-xss/ referenced PoC, tagged "exploit" by a source, unverified
- shielder.it https://www.shielder.it/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
Affected products
- QNAP Systems Inc. Q’center
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
shielder.it
/advisories/qnap-qcenter-virtual-stored-xss/
exploit, third-party-advisory
-
shielder.it
/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/
exploit, third-party-advisory
-
qnap.com
/zh-tw/security-advisory/qsa-21-20
vendor-advisory
Sources
- CVE List CVE-2021-28807
- NVD CVE-2021-28807
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.