CVE-2021-20589: Buffer access with incorrect length value vulnerability in GOT2000 series GT27 model communication driver vers
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HIGH 7.5REMOTEUPGRADEUPGRADEUPGRADE
CVE-2021-20589 is a high-severity flaw (CVSS 7.5) affecting gt27 firmware, gt25 firmware, gt23 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 So
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
Published CVE record published
Updated Record last modified
mitsubishi gt27 firmware UPGRADE
Affected: >= 01.19.000 and <= 01.38.000
Fixed in: newer than 01.38.000
Safe to downgrade to: a release before 01.19.000
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
mitsubishi gt25 firmware UPGRADE
Affected: >= 01.19.000 and <= 01.38.000
Fixed in: newer than 01.38.000
Safe to downgrade to: a release before 01.19.000
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
mitsubishi gt23 firmware UPGRADE
Affected: >= 01.19.000 and <= 01.38.000
Fixed in: newer than 01.38.000
Safe to downgrade to: a release before 01.19.000
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
mitsubishi gt21 firmware UPGRADE
Affected: >= 01.21.000 and <= 01.39.000
Fixed in: newer than 01.39.000
Safe to downgrade to: a release before 01.21.000
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
mitsubishi gs21 firmware UPGRADE
Affected: >= 01.21.000 and <= 01.39.000
Fixed in: newer than 01.39.000
Safe to downgrade to: a release before 01.21.000
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
mitsubishi gt softgot2000 firmware UPGRADE
Affected: >= 1.170c and <= 1.250l
Fixed in: newer than 1.250l
Safe to downgrade to: a release before 1.170c
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
Verify at the official sourceNVD · CVE Program · Report a problem with this page Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-20589?
gt27 firmware: upgrade to newer than 01.38.000; gt25 firmware: upgrade to newer than 01.38.000; gt23 firmware: upgrade to newer than 01.38.000. Exact commands for each OS are on this page.
Is CVE-2021-20589 being exploited?
CVE-2021-20589 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-20589 affect?
CVE-2021-20589 affects gt27 firmware, gt25 firmware, gt23 firmware. Severity is high (CVSS 7.5). 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 d
How urgent is CVE-2021-20589?
Priority 50/100. High severity; Remotely exploitable, no login, no user action
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