CVE-2021-20589

Buffer access with incorrect length value vulnerability in GOT2000 series GT27 model communication driver versions 01.19.000 through 01.38.000, GT25 model communication driver versions 01.19.000 through 01.38.000, GT23 model communication driver versions 01.19.000 through 01.38.000 and GT21 model communication driver versions 01.21.000 through 01.39.000, GOT SIMPLE series GS21 model communication driver versions 01.21.000 through 01.39.000, GT SoftGOT2000 versions 1.170C through 1.250L and Tension Controller LE7-40GU-L Screen package data for MODBUS/TCP V1.00 allows a remote unauthenticated attacker to stop the communication function of the products via specially crafted packets.

Published: 2021-05-19 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20589 is rated Moderate Risk (49.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.33%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-20589

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.23% 0.33% +0.09%
2 2025-11-18 0.33% 0.23% -0.09%
3 2025-03-30 — 0.33% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20589

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-20589

Affected software / configurations for CVE-2021-20589

Vendor Product Version Raw CPE
mitsubishi gt27_firmware >= 01.19.000, <= 01.38.000 cpe:2.3:o:mitsubishi:gt27_firmware:*:*:*:*:*:*:*:*
mitsubishi gt25_firmware >= 01.19.000, <= 01.38.000 cpe:2.3:o:mitsubishi:gt25_firmware:*:*:*:*:*:*:*:*
mitsubishi gt23_firmware >= 01.19.000, <= 01.38.000 cpe:2.3:o:mitsubishi:gt23_firmware:*:*:*:*:*:*:*:*
mitsubishi gt21_firmware >= 01.21.000, <= 01.39.000 cpe:2.3:o:mitsubishi:gt21_firmware:*:*:*:*:*:*:*:*
mitsubishi gs21_firmware >= 01.21.000, <= 01.39.000 cpe:2.3:o:mitsubishi:gs21_firmware:*:*:*:*:*:*:*:*
mitsubishi gt_softgot2000_firmware >= 1.170c, <= 1.250l cpe:2.3:o:mitsubishi:gt_softgot2000_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-20589

cvelogic Threat Intelligence