CVE-2021-20700

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 Disk Agent 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

related (5,668)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2025-43520US	medium5.5OT critical	0.43% (37th)	KEV	2025-12-12
A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.2 and iPadOS 18.7.2, iOS 26.1 and iPadOS 26.1, macOS Sequoia 15.7.2, macOS So…
CVE-2025-20333US	—OT critical	71.2% (99th)	KEV	2025-09-25
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an aut…
CVE-2025-39682US	critical9.8OT critical	3.25% (88th)	KEV	2025-09-05
In the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contig…
CVE-2025-31277US	—OT critical	1.66% (77th)	KEV	2025-07-30
The issue was addressed with improved memory handling. This issue is fixed in Safari 18.6, iOS 18.6 and iPadOS 18.6, macOS Sequoia 15.6, tvOS 18.6, visionOS 2.6, watchOS 11.6. Proc…
CVE-2025-24985US	—OT critical	3.89% (90th)	KEV	2025-03-11
Integer overflow or wraparound in Windows Fast FAT Driver allows an unauthorized attacker to execute code locally.

+5663 more

references (7)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan