Is CVE-2021-28800 actively exploited?

No active exploitation of CVE-2021-28800 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-28800 be exploited remotely?

Yes. CVE-2021-28800 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-28800?

CVE-2021-28800 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-28800

CRITICAL

CVE-2021-28800

CWE-78Published: June 24, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

A command injection vulnerability has been reported to affect QNAP NAS running legacy versions of QTS. If exploited, this vulnerability allows attackers to execute arbitrary commands in a compromised application. This issue affects: QNAP Systems Inc. QTS versions prior to 4.3.6.1663 Build 20210504; versions prior to 4.3.3.1624 Build 20210416. This issue does not affect: QNAP Systems Inc. QTS 4.5.3. QNAP Systems Inc. QuTS hero h4.5.3. QNAP Systems Inc. QuTScloud c4.5.5.

NVD Source

Technical Analysis

CVE-2021-28800 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.