CVE-2021-28809

Missing Authentication for Critical Function in RTRR Server in HBS3

Severity Score

9.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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

Se ha informado una vulnerabilidad de control de acceso inapropiado que afecta a determinadas versiones heredadas de HBS 3. Si es explotada, esta vulnerabilidad permite a atacantes comprometer la seguridad del sistema operativo.QNAP ya ha corregido esta vulnerabilidad en las siguientes versiones de HBS 3: QTS versiones 4.3.6: HBS 3 versiones v3.0.210507 y posteriores QTS versiones 4.3.4: HBS 3 versiones v3.0.210506 y posteriores

This vulnerability allows remote attackers to execute arbitrary code on affected installations of QNAP NAS. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the RTSS server, which listens on TCP port 8899 by default. The issue results from the lack of authentication prior to allowing alterations to the system configuration. An attacker can leverage this vulnerability to execute arbitrary code in the context of the Administrator.

*Credits: Ta-Lun Yen of TXOne IoT/ICS Security Research Labs of Trend Micro working with Trend Micro’s Zero Day Initiative

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-03-18 CVE Reserved
2021-07-08 CVE Published
2024-02-26 EPSS Updated
2024-09-17 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-284: Improper Access Control
CWE-306: Missing Authentication for Critical Function
CWE-749: Exposed Dangerous Method or Function

CAPEC

References (2)

URL	Tag	Source
https://www.zerodayinitiative.com/advisories/ZDI-21-783	Third Party Advisory

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.qnap.com/en/security-advisory/qsa-21-19	2021-07-12

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Qnap Search vendor "Qnap"	Hybrid Backup Sync Search vendor "Qnap" for product "Hybrid Backup Sync"	< 3.0.210507 Search vendor "Qnap" for product "Hybrid Backup Sync" and version " < 3.0.210507"	-	Affected	in	Qnap Search vendor "Qnap"	Qts Search vendor "Qnap" for product "Qts"	4.3.6 Search vendor "Qnap" for product "Qts" and version "4.3.6"	-	Safe
Qnap Search vendor "Qnap"	Hybrid Backup Sync Search vendor "Qnap" for product "Hybrid Backup Sync"	< 3.0.210506 Search vendor "Qnap" for product "Hybrid Backup Sync" and version " < 3.0.210506"	-	Affected	in	Qnap Search vendor "Qnap"	Qts Search vendor "Qnap" for product "Qts"	4.3.4 Search vendor "Qnap" for product "Qts" and version "4.3.4"	-	Safe
Qnap Search vendor "Qnap"	Hybrid Backup Sync Search vendor "Qnap" for product "Hybrid Backup Sync"	< 3.0.210506 Search vendor "Qnap" for product "Hybrid Backup Sync" and version " < 3.0.210506"	-	Affected	in	Qnap Search vendor "Qnap"	Qts Search vendor "Qnap" for product "Qts"	4.3.3 Search vendor "Qnap" for product "Qts" and version "4.3.3"	-	Safe