CVE-2021-28809
Published: 08 July 2021
Summary
CVE-2021-28809 is a critical-severity Improper Access Control (CWE-284) vulnerability in Qnap Hybrid Backup Sync. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 30.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-15465
Vulnerability details
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…
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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
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Restricting available functions and services reduces the attack surface and enforces proper access control boundaries.
Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.
Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.
Requiring authorization and configuration controls for mobile device connections directly enforces access control and prevents unauthorized devices from reaching organizational systems.
Provides a tamperproof, always-invoked, and verifiable mechanism to enforce access control policies.
Provides capability to review session content, directly detecting violations of access control.
Control assessments verify that access controls are implemented correctly and operating as intended, detecting improper access control before exploitation.
Certification requires independent assessment confirming access controls are implemented correctly and effective.