CVE-2021-28799 KEV
10.0
CRITICAL · CVSS 3.1 · EPSS 78.3% (pctl 100)
Patch first
On CISA KEV — known exploited in the wild, due 2022-04-21.
Description
An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If exploited, the vulnerability allows remote attackers to log in to a device. This issue affects: QNAP Systems Inc. HBS 3 versions prior to v16.0.0415 on QTS 4.5.2; versions prior to v3.0.210412 on QTS 4.3.6; versions prior to v3.0.210411 on QTS 4.3.4; versions prior to v3.0.210411 on QTS 4.3.3; versions prior to v16.0.0419 on QuTS hero h4.5.1; versions prior to v16.0.0419 on QuTScloud c4.5.1~c4.5.4. This issue does not affect: QNAP Systems Inc. HBS 2 . QNAP Systems Inc. HBS 1.3 .
Scoring
| CVSS | 10.0 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| EPSS | 78.25% — more likely to be exploited than 100% of all CVEs |
| Weakness | CWE-285 |
| On CISA KEV | yes — remediate by 2022-04-21 |
| Public exploit | none known |
| Published | 2021-05-13 |
| Last modified | 2026-06-17 |
CISA KEV
| Name | QNAP NAS Improper Authorization Vulnerability |
|---|---|
| Added | 2022-03-31 |
| Due | 2022-04-21 |
| Vendor / product | QNAP / Network Attached Storage (NAS) |
| Ransomware use | known |
Affected (4)
| Vendor | Product |
|---|---|
| qnap | hybrid backup sync |
| qnap | qts |
| qnap | quts hero |
| qnap | qutscloud |
References
→ the Explorer · watch your stack · NVD