VDB-173867 · CVE-2021-28799 · GCVE-0-2021-28799

QNAP QTS/QuTS Hero/QuTScloud HBS 3 Hybrid Backup Sync improper authorization

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.6	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in QNAP QTS, QuTS Hero and QuTScloud. Affected by this issue is some unknown functionality of the component HBS 3 Hybrid Backup Sync. The manipulation leads to improper authorization. This vulnerability is uniquely identified as CVE-2021-28799. The attack is possible to be carried out remotely. Moreover, an exploit is present. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in QNAP QTS, QuTS Hero and QuTScloud (Network Attached Storage Software) (affected version unknown) and classified as critical. This issue affects an unknown functionality of the component HBS 3 Hybrid Backup Sync. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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 .

The weakness was disclosed 04/25/2021. The identification of this vulnerability is CVE-2021-28799. Technical details are unknown but an exploit is available. The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

It is declared as attacked. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 03/31/2022 with a due date of 04/21/2022:

Apply updates per vendor instructions.

Upgrading eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Network Attached Storage Software

Vendor

QNAP

Name

License

commercial

Website

Vendor: https://www.qnap.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.7
VulDB Meta Temp Score: 8.6

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CNA Base Score: 10.0
CNA Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Improper authorization
CWE: CWE-285 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

03/18/2021 🔍
04/25/2021 +37 days 🔍
04/25/2021 +0 days 🔍
03/12/2025 +1417 days 🔍

Sourcesinfo

Vendor: qnap.com

Status: Confirmed

CVE: CVE-2021-28799 (🔍)
GCVE (CVE): GCVE-0-2021-28799
GCVE (VulDB): GCVE-100-173867
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 04/25/2021 20:46
Updated: 03/12/2025 23:23
Changes: 04/25/2021 20:46 (36), 04/29/2021 14:29 (4), 04/25/2024 08:27 (26), 09/19/2024 18:18 (2), 03/12/2025 23:23 (29)
Complete: 🔍
Cache ID: 216::103