CVE-2021-28799 Scanner
CVE-2021-28799 Scanner - Improper Access Control vulnerability in Hybrid Backup Sync (HBS 3)
Used 3.5k times · 3.3k assets checked · domain, subdomain, ipv4
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CISA Known Exploited Vulnerability
This CVE is actively exploited in the wild. CISA mandates federal agencies to patch immediately.
CVE
CVE-2021-28799
9.8
CVSScritical
Exploitable remotely over the internet · no authentication required.
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 .
Attack Vector
Network
Privileges Req.
None
User Interaction
None
hbs 3hbs 2hbs 1.3
Updated Sep 26, 2026View on NVD →
S4E scanner
CVE history: hbs 3
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