CVE-2024-21899Network attack vector

Authenticated system compromise

Published Mar 8, 2024 · Updated Aug 1, 2024

Improper authentication in QNAP QTS, QuTS hero, and QuTScloud allows remote authenticated users to compromise systems over a network. QNAP has not disclosed the affected authentication component or the incorrect operation that accepts an authenticated user's network request. A valid user account is required, and the vendor reports a system-wide security compromise without specifying the resulting actions or data exposure.

CVSS severity9.8
Critical
EPSS probability24.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in QNAP QTS, QuTS hero, and QuTScloud allows remote authenticated users to compromise systems over a network. QNAP has not disclosed the affected authentication component or the incorrect operation that accepts an authenticated user's network request. A valid user account is required, and the vendor reports a system-wide security compromise without specifying the resulting actions or data exposure.

The record

CVE
CVE-2024-21899
Published
Mar 8, 2024
Updated
Aug 1, 2024
Vendor
Linn Products Limited
Product
QuTS hero
Classifications
CWE-287
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 8, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=h4.5.0 <h4.5.4.2626 build 20231225
  2. Affected versionversion=h4.5.x <h4.5.4.2626 build 20231225
  3. Affected versionversion=h5.1.0 <h5.1.3.2578 build 20231110
  4. Affected versionversion=h5.1.x <h5.1.3.2578 build 20231110

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Linn Products Limited · QuTS heroversion=h4.5.0 <h4.5.4.2626 build 20231225; version=h4.5.x <h4.5.4.2626 build 20231225; version=h5.1.0 <h5.1.3.2578 build 20231110; version=h5.1.x <h5.1.3.2578 build 20231110
Linn Products Limited · QuTScloudversion=c5.0.0 <c5.1.5.2651; version=c5.x.x <c5.1.5.2651
Linn Products Limited · QTSversion=4.5.0 <4.5.4.2627 build 20231225; version=4.5.x <4.5.4.2627 build 20231225; version=5.1.0 <5.1.3.2578 build 20231110; version=5.1.x <5.1.3.2578 build 20231110

Published CVSS scores

9.8QNAP Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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