How severe is CVE-2021-20589?

CVE-2021-20589 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-20589 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20589?

CVE-2021-20589 primarily affects Mitsubishi Gt27 Firmware. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20589?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-20589 published?

CVE-2021-20589 was published on 2021-05-19 and last updated on 2026-06-17.

CVE-2021-20589

CVE-2021-20589 is a high-severity vulnerability in Mitsubishi Gt27 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Mitsubishi Gt27 Firmware
Published: 2021-05-19
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2021-20589?: CVE-2021-20589 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-20589 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20589?: CVE-2021-20589 primarily affects Mitsubishi Gt27 Firmware. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20589?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-20589 published?: CVE-2021-20589 was published on 2021-05-19 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:o:mitsubishi:gt27_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishi:gt25_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishi:gt23_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishi:gt21_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishi:gs21_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishi:gt_softgot2000_firmware:*:*:*:*:*:*:*:*

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