CVE-2021-28801

Sensitive information disclosure via out-of-bounds read

Published Jun 11, 2021 · Updated Sep 17, 2024

An out-of-bounds read in QNAP Systems QSS before 1.0.2 build 20210122 allows remote attackers to read sensitive system information. QNAP identifies an out-of-bounds memory read but has not published the affected component, the input that crosses its boundary, or the request path that reaches it. Exploitation is reachable from an adjacent network without authentication or user interaction; the disclosed consequence is limited to reading sensitive information.

CVSS severity3.1
Low
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

An out-of-bounds read in QNAP Systems QSS before 1.0.2 build 20210122 allows remote attackers to read sensitive system information. QNAP identifies an out-of-bounds memory read but has not published the affected component, the input that crosses its boundary, or the request path that reaches it. Exploitation is reachable from an adjacent network without authentication or user interaction; the disclosed consequence is limited to reading sensitive information.

The record

CVE
CVE-2021-28801
Published
Jun 11, 2021
Updated
Sep 17, 2024
Vendor
Linn Products Limited
Product
QNAP Switch System
Classifications
CWE-125
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=unspecified <1.0.2 build 20210122

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Linn Products Limited · QNAP Switch Systemversion=unspecified <1.0.2 build 20210122

Published CVSS scores

3.1QNAP Systems, Inc.CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo