CVE-2021-28809
9.8
CRITICAL · CVSS 3.1 · EPSS 16.1% (pctl 97)
Patch early
EPSS 16.1% — above the 10% action threshold.
Description
An improper access control vulnerability has been reported to affect certain legacy versions of HBS 3. If exploited, this vulnerability allows attackers to compromise the security of the operating system.QNAP have already fixed this vulnerability in the following versions of HBS 3: QTS 4.3.6: HBS 3 v3.0.210507 and later QTS 4.3.4: HBS 3 v3.0.210506 and later QTS 4.3.3: HBS 3 v3.0.210506 and later
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 16.09% — more likely to be exploited than 97% of all CVEs |
| Weakness | CWE-284 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2021-07-08 |
| Last modified | 2026-06-17 |
Affected (2)
| Vendor | Product |
|---|---|
| qnap | hybrid backup sync |
| qnap | qts |
References
→ the Explorer · watch your stack · NVD