CVE-2021-20589: Mitsubishi GS21 Firmware

High severity, CVSS 7.5. EPSS: 1.5% chance of exploitation in the next 30 days.

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.

Affected products

• Mitsubishi GS21 Firmware: from 01.21.000, up to and including 01.39.000
• Mitsubishi GT21 Firmware: from 01.21.000, up to and including 01.39.000
• Mitsubishi GT23 Firmware: from 01.19.000, up to and including 01.38.000
• Mitsubishi GT25 Firmware: from 01.19.000, up to and including 01.38.000
• Mitsubishi GT27 Firmware: from 01.19.000, up to and including 01.38.000
• Mitsubishi Gt SOFTGOT2000 Firmware: from 1.170c, up to and including 1.250l

Published 2021-05-19. Last modified 2026-06-17.