Vulnerability Monitor

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CVE-2021-28807

A post-authentication reflected XSS vulnerability has been reported to affect QNAP NAS running Q’center. If exploited, this vulnerability allows remote attackers to inject malicious code. QNAP have already fixed this vulnerability in the following versions of Q’center: QTS 4.5.3: Q’center v1.12.1012 and later QTS 4.3.6: Q’center v1.10.1004 and later QTS 4.3.3: Q’center v1.10.1004 and later QuTS hero h4.5.2: Q’center v1.12.1012 and later QuTScloud c4.5.4: Q’center v1.12.1012 and later

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.7, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 4 products from qnap, from qnap, from qnap and 1 other, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-06-03T03:15:08.533

Last Modified

2024-11-21T06:00:14.463

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.7 (HIGH)

CVSSv2 Vector

AV:N/AC:M/Au:S/C:N/I:P/A:N

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: SINGLE
Confidentiality Impact: NONE
Integrity Impact: PARTIAL
Availability Impact: NONE

Exploitability Score

6.8

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-79

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	qnap	q\'center	< 1.12.1012	Yes
Operating System	qnap	qts	4.5.3	No
Application	qnap	q\'center	< 1.10.1004	Yes
Operating System	qnap	qts	4.3.3	No
Application	qnap	q\'center	< 1.10.1004	Yes
Operating System	qnap	qts	4.3.6	No
Application	qnap	q\'center	< 1.12.1012	Yes
Operating System	qnap	quts_hero	h4.5.2	No
Application	qnap	q\'center	< 1.12.1012	Yes
Operating System	qnap	qutscloud	c4.5.4	No

References

https://www.qnap.com/zh-tw/security-advisory/qsa-21-20 Vendor Advisory ([email protected])
https://www.shielder.it/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/ Exploit, Third Party Advisory ([email protected])
https://www.shielder.it/advisories/qnap-qcenter-virtual-stored-xss/ Exploit, Third Party Advisory ([email protected])
https://www.qnap.com/zh-tw/security-advisory/qsa-21-20 Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.shielder.it/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/ Exploit, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.shielder.it/advisories/qnap-qcenter-virtual-stored-xss/ Exploit, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For qnap's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.