CVE-2021-28804 | Command Injection Vulnerabilities in QTS and QuTS hero

A command injection vulnerabilities have been reported to affect QTS and QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary commands in a compromised application. This issue affects: QNAP Systems Inc. QTS versions prior to 4.5.1.1540 build 20210107. QNAP Systems Inc. QuTS hero versions prior to h4.5.1.1582 build 20210217.

Published: 2021-07-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-28804 is rated High Risk (69.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.75%). High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-28804

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-06 2.17% 2.75% +0.57%
2 2025-11-21 3.26% 2.17% -1.09%
3 2025-11-18 — 3.26% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28804

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2021-28804

Affected software / configurations for CVE-2021-28804

Vendor Product Version Raw CPE
qnap qts <= 4.5.1.1540 cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
qnap quts_hero <= h4.5.1.1582 cpe:2.3:o:qnap:quts_hero:*:*:*:*:*:*:*:*

References for CVE-2021-28804

cvelogic Threat Intelligence