CVE-2021-38408

highpriority · track · 43EPSS 0.116 · 96 %ileEURUUS

grimoire priorityP1 · Urgent

Exploitable?

—

no known exploitation

Likely / severe?

11.6% (96th) EPSS

CVSS 7.5 · high

Is it mine?

5 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

A stack-based buffer overflow vulnerability in Advantech WebAccess Versions 9.02 and prior caused by a lack of proper validation of the length of user-supplied data may allow remote code execution.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

No vendor fix yet; a mitigation is available.

MitigationWebAccesscisa_csaf_ot
Advantech is actively working on a solution to mitigate this vulnerability and intends to release an updated version when available.

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

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · CISA US

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

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-121USCWE-121USCWE-121US

affected products (5)

Products and version ranges known to be affected.

WebAccess: Versions 9.02 and priorall versionscisa_csaf_otUS
Advantech WebAccess≤ 9.02cisa_csaf_otUS
n/a Advantech WebAccess≤ WebAccess: Versions 9.02 and priorenisa_euvdEU
Advantech Co., Ltd Advantech WebAccess≤ 9.02fstec_bduRU
advantech webaccess≤ 9.02nvdUScpe:2.3:a:advantech:webaccess:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

ICSA-21-245-03Advantech WebAccess2021-09-02icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability may allow remote code execution.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisa_csaf_ot nvd NVD CVE.org MITRE

published 2021-09-09modified 2026-06-17

references (7)

External citations — patches, advisories, analysis.

scry

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