CVE-2021-28809 in the critical feed json
Missing Authentication for Critical Function in RTRR Server in HBS3
published 2021-07-08 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-15465
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 16.1%
- EPSS 16.1% chance of exploitation in 30 days, percentile 96%
- public exploits
- 0
- none known
Summary
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
Patch / fix
- QNAP Systems Inc. HBS 3 v3.0.210506, v3.0.210507
Exploit prediction
16.09% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 10.0 | AV:N/AC:L/Au:N/C:C/I:C/A:C |
Affected products
- QNAP Systems Inc. HBS 3
Classification
References
-
qnap.com
/en/security-advisory/qsa-21-19
vendor-advisory
-
zerodayinitiative.com
/advisories/ZDI-21-783/
third-party-advisory, vdb-entry
Sources
- CVE List CVE-2021-28809
- NVD CVE-2021-28809
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