CVE-2021-28797

highpriority · track · 41EPSS 0.059 · 93 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

5.91% (93rd) EPSS

CVSS 7.5 · high

Is it mine?

4 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-28

A stack-based buffer overflow vulnerability has been reported to affect QNAP NAS devices running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. QNAP have already fixed this vulnerability in the following versions: Surveillance Station 5.1.5.4.3 (and later) for ARM CPU NAS (64bit OS) and x86 CPU NAS (64bit OS) Surveillance Station 5.1.5.3.3 (and later) for ARM CPU NAS (32bit OS) and x86 CPU NAS (32bit OS)

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · security@qnapsecurity.com.twexploitability 3.9 · impact 5.9

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-121US

affected products (4)

Products and version ranges known to be affected.

QNAP Systems Inc. Surveillance Stationunspecified → 5.1.5.3.3enisa_euvdEU
QNAP Systems Inc. Surveillance Stationunspecified → 5.1.5.4.3enisa_euvdEU
qnap surveillance station< 5.1.5.3.3nvdUScpe:2.3:a:qnap:surveillance_station:*:*:*:*:*:*:*:*
qnap surveillance station5.1.5.4.0 → 5.1.5.4.3nvdUScpe:2.3:a:qnap:surveillance_station:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-04-14modified 2026-06-17

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+16132 more

references (4)

External citations — patches, advisories, analysis.

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