Vulnerability Name:

CVE-2021-28809 (CCN-204911)

Assigned:2021-07-06
Published:2021-07-06
Updated:2021-07-12
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
CVSS v3 Severity:9.8 Critical (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
8.5 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
9.8 Critical (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
8.5 High (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
CVSS v2 Severity:10.0 High (CVSS v2 Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): Complete
10.0 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): Complete
Vulnerability Type:CWE-284
CWE-749
CWE-306
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2021-28809

Source: XF
Type: UNKNOWN
qnap-cve202128809-sec-bypass(204911)

Source: CCN
Type: QNAP QSA-21-19
Improper Access Control Vulnerability in Legacy HBS 3 (Hybrid Backup Sync)

Source: MISC
Type: Vendor Advisory
https://www.qnap.com/en/security-advisory/qsa-21-19

Source: CCN
Type: ZDI-21-783
QNAP NAS Hybrid Backup Missing Authentication for Critical Function Remote Code Execution Vulnerability

Source: MISC
Type: Third Party Advisory, VDB Entry
https://www.zerodayinitiative.com/advisories/ZDI-21-783/

Vulnerable Configuration:Configuration 1:
  • cpe:/a:qnap:hybrid_backup_sync:*:*:*:*:*:*:*:* (Version < 3.0.210507)
  • AND
  • cpe:/o:qnap:qts:4.3.6:-:*:*:*:*:*:*

    • Configuration 2:
  • cpe:/a:qnap:hybrid_backup_sync:*:*:*:*:*:*:*:* (Version < 3.0.210506)
  • AND
  • cpe:/o:qnap:qts:4.3.4:-:*:*:*:*:*:*

    • Configuration 3:
  • cpe:/a:qnap:hybrid_backup_sync:*:*:*:*:*:*:*:* (Version < 3.0.210506)
  • AND
  • cpe:/o:qnap:qts:4.3.3:-:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/h:qnap:nas:-:*:*:*:*:*:*:*
  • OR cpe:/a:qnap:qts:4.3.3:*:*:*:*:*:*:*
  • OR cpe:/a:qnap:qts:4.3.4:*:*:*:*:*:*:*
  • OR cpe:/a:qnap:qts:4.3.6:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    qnap hybrid backup sync *
    qnap qts 4.3.6 -
    qnap hybrid backup sync *
    qnap qts 4.3.4 -
    qnap hybrid backup sync *
    qnap qts 4.3.3 -
    qnap nas -
    qnap qts 4.3.3
    qnap qts 4.3.4
    qnap qts 4.3.6