CVE-2021-20608

mediumpriority · track · 31EPSS 0.029 · 87 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.88% (87th) EPSS

CVSS 5 · medium

Is it mine?

4 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-27

Improper Handling of Length Parameter Inconsistency vulnerability in Mitsubishi Electric GX Works2 versions 1.606G and prior allows a remote unauthenticated attacker to cause a DoS condition in GX Works2 by getting GX Works2 to read a tampered program file from a Mitsubishi Electric PLC by sending malicious crafted packets to tamper with the program file.

remediations

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

A vendor fix is available.

FixedGX Works2cisa_csaf_ot
GX Works2, version 1.610L or later
https://www.mitsubishielectric.com/fa/#software
MitigationGX Works2cisa_csaf_ot
Locate control system networks and remote devices behind firewalls and isolate them from the business network.

cvss

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

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.05.3mediumCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · CISA US

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-130US

affected products (4)

Products and version ranges known to be affected.

GX Works2: Versions 1.606G and priorall versionscisa_csaf_otUS
Mitsubishi Electric GX Works2≤ 1.606Gcisa_csaf_otUS
n/a GX Works2≤ versions 1.606G and priorenisa_euvdEU
mitsubishielectric gx works2≤ 1.606gnvdUScpe:2.3:a:mitsubishielectric:gx_works2:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

ICSA-21-350-04Mitsubishi Electric GX Works22021-12-16icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability may cause a denial-of-service condition in GX Works2.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot nvd NVD CVE.org MITRE

published 2021-12-17modified 2026-06-17

references (12)

External citations — patches, advisories, analysis.

scry

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