CVE-2024-21899 | QTS, QuTS hero, QuTScloud

An improper authentication vulnerability has been reported to affect several QNAP operating system versions. If exploited, the vulnerability could allow users to compromise the security of the system via a network. We have already fixed the vulnerability in the following versions: QTS 5.1.3.2578 build 20231110 and later QTS 4.5.4.2627 build 20231225 and later QuTS hero h5.1.3.2578 build 20231110 and later QuTS hero h4.5.4.2626 build 20231225 and later QuTScloud c5.1.5.2651 and later

Published: 2024-03-08 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-21899 is rated High Risk (78.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 24.37%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +12.96% over the last day, indicating growing attacker interest. 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-2024-21899

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 2026-06-15 11.41% 24.37% +12.96%
2 2026-03-27 10.59% 11.41% +0.82%
3 2026-01-28 — 10.59% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-21899

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]
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]

Weakness enumeration for CVE-2024-21899

Affected software / configurations for CVE-2024-21899

Vendor Product Version Raw CPE
qnap qts < 4.5.4.2627 cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
qnap qts >= 5.1.0, < 5.1.3.2578 cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
qnap qts 4.5.4.2627 cpe:2.3:o:qnap:qts:4.5.4.2627:-:*:*:*:*:*:*
qnap qts 5.1.3.2578 cpe:2.3:o:qnap:qts:5.1.3.2578:-:*:*:*:*:*:*
qnap quts_hero < h4.5.4.2626 cpe:2.3:o:qnap:quts_hero:*:*:*:*:*:*:*:*
qnap quts_hero >= h5.1.0, < h5.1.3.2578 cpe:2.3:o:qnap:quts_hero:*:*:*:*:*:*:*:*
qnap quts_hero h4.5.4.2626 cpe:2.3:o:qnap:quts_hero:h4.5.4.2626:-:*:*:*:*:*:*
qnap quts_hero h5.1.3.2578 cpe:2.3:o:qnap:quts_hero:h5.1.3.2578:-:*:*:*:*:*:*
qnap qutscloud < c5.1.5.2651 cpe:2.3:o:qnap:qutscloud:*:*:*:*:*:*:*:*

References for CVE-2024-21899

cvelogic Threat Intelligence