CVE-2021-28809
CRITICALQNAP Hybrid Backup Sync < 3.0.210507 - Improper Access Control
Title source: llmDescription
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
References (2)
Core 2
Core References
Vendor Advisory x_refsource_misc
https://www.qnap.com/en/security-advisory/qsa-21-19
Third Party Advisory, VDB Entry x_refsource_misc
https://www.zerodayinitiative.com/advisories/ZDI-21-783/
Scores
CVSS v3
9.8
EPSS
0.1568
EPSS Percentile
96.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-284
CWE-306
CWE-749
Status
published
Products (1)
qnap/hybrid_backup_sync
< 3.0.210507
Published
Jul 08, 2021
Tracked Since
Feb 18, 2026