CVEs / CVE-2021-28799
CVE-2021-28799: QNAP NAS Improper Authorization Vulnerability
- Known exploited in the CISA KEV catalog since 31 Mar 2022
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 78.2% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
QNAP NAS running HBS 3 contains an improper authorization vulnerability which can allow remote attackers to log in to a device.
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 .
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc. HBS 3 | from unspecified, before v16.0.0415 | v16.0.0415 |
| QNAP Systems Inc. HBS 3 | from unspecified, before v3.0.210412 | v3.0.210412 |
| QNAP Systems Inc. HBS 3 | from unspecified, before v3.0.210411 | v3.0.210411 |
| QNAP Systems Inc. HBS 3 | from unspecified, before v16.0.0419 | v16.0.0419 |
Exploitation
| In CISA KEV since | 31 Mar 2022 |
|---|---|
| Due date for US federal agencies | 21 Apr 2022 |
| Used in ransomware campaigns | Known |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-285 |
References
- CVE-2021-28799 on NVD
- CVE-2021-28799 in the CISA KEV catalog
- https://www.qnap.com/en/security-advisory/QSA-21-13 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-28799 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.