CVE-2021-20704

highpriority · track · 40EPSS 0.021 · 82 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

2.14% (82nd) EPSS

CVSS 7.5 · high

Is it mine?

5 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

Buffer overflow vulnerability in the compatible API with previous versions CLUSTERPRO X 4.3 for Windows and earlier, EXPRESSCLUSTER X 4.3 for Windows and earlier, CLUSTERPRO X 4.3 SingleServerSafe for Windows and earlier, EXPRESSCLUSTER X 4.3 SingleServerSafe for Windows and earlier allows attacker to remote code execution via a network.

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

v3.19criticalCVSS: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-120USprimary

affected products (5)

Products and version ranges known to be affected.

NEC Corporation CLUSTERPRO X≤ CLUSTERPRO X 4.3 for Windows and earlier, EXPRESSCLUSTER X 4.3 for Windows and earlier, CLUSTERPRO X 4.3 SingleServerSafe for Windows and earlier, EXPRESSCLUSTER X 4.3 SingleServerSafe for Windows and earlierenisa_euvdEU
nec clusterpro x1.0 → 4.3nvdUScpe:2.3:a:nec:clusterpro_x:*:*:*:*:*:*:*:*
nec clusterpro x singleserversafe1.0 → 4.3nvdUScpe:2.3:a:nec:clusterpro_x_singleserversafe:*:*:*:*:*:*:*:*
nec expresscluster x1.0 → 4.3nvdUScpe:2.3:a:nec:expresscluster_x:*:*:*:*:*:*:*:*
nec expresscluster x singleserversafe1.0 → 4.3nvdUScpe:2.3:a:nec:expresscluster_x_singleserversafe:*:*:*:*:*:*:*:*

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 2021-11-03modified 2026-06-17

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+5663 more

references (5)

External citations — patches, advisories, analysis.

scry

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