CVE-2021-38692Network attack vector

Unauthenticated code execution via stack buffer overflow

Published Jan 14, 2022 · Updated Sep 16, 2024

Stack buffer overflow in QNAP QVR Elite before 2.1.4.0 and QVR Pro and QVR Guard before 2.1.3.0 allows remote attackers to execute code. QNAP has not published the affected component, input field, or unchecked copy operation that overruns the stack buffer. Unauthenticated network access is sufficient, and successful exploitation runs arbitrary code on the NAS-hosted surveillance service.

CVSS severity8.1
High
EPSS probability1.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in QNAP QVR Elite before 2.1.4.0 and QVR Pro and QVR Guard before 2.1.3.0 allows remote attackers to execute code. QNAP has not published the affected component, input field, or unchecked copy operation that overruns the stack buffer. Unauthenticated network access is sufficient, and successful exploitation runs arbitrary code on the NAS-hosted surveillance service.

The record

CVE
CVE-2021-38692
Published
Jan 14, 2022
Updated
Sep 16, 2024
Vendor
Linn Products Limited
Product
QVR Guard
Classifications
CWE-787, CWE-120, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <2.1.3.0 (2021/12/06)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Linn Products Limited · QVR Guardversion=unspecified <2.1.3.0 (2021/12/06)
Linn Products Limited · QVR Eliteversion=unspecified <2.1.4.0 (2021/12/06)
Linn Products Limited · QVR Proversion=unspecified <2.1.3.0 (2021/12/06)

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1QNAP Systems, Inc.CVSS:3.1/AV:N/AC:H/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1210Exploitation of Remote Services

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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