CVE-2021-20588
CWE-130Published: February 19, 2021· Updated: Jun 17, 2026
Official Description
Improper Handling of Length Parameter Inconsistency vulnerability in Mitsubishi Electric FA Engineering Software (CPU Module Logging Configuration Tool versions 1.112R and prior, CW Configurator versions 1.011M and prior, Data Transfer versions 3.44W and prior, EZSocket versions 5.4 and prior, FR Configurator all versions, FR Configurator SW3 all versions, FR Configurator2 versions 1.24A and prior, GT Designer3 Version1(GOT1000) versions 1.250L and prior, GT Designer3 Version1(GOT2000) versions 1.250L and prior, GT SoftGOT1000 Version3 versions 3.245F and prior, GT SoftGOT2000 Version1 versions 1.250L and prior, GX Configurator-DP versions 7.14Q and prior, GX Configurator-QP all versions, GX Developer versions 8.506C and prior, GX Explorer all versions, GX IEC Developer all versions, GX LogViewer versions 1.115U and prior, GX RemoteService-I all versions, GX Works2 versions 1.597X and prior, GX Works3 versions 1.070Y and prior, iQ Monozukuri ANDON (Data Transfer) versions 1.003D and prior, iQ Monozukuri Process Remote Monitoring (Data Transfer) versions 1.002C and prior, M_CommDTM-HART all versions, M_CommDTM-IO-Link versions 1.03D and prior, MELFA-Works versions 4.4 and prior, MELSEC WinCPU Setting Utility all versions, MELSOFT EM Software Development Kit (EM Configurator) versions 1.015R and prior, MELSOFT Navigator versions 2.74C and prior, MH11 SettingTool Version2 versions 2.004E and prior, MI Configurator versions 1.004E and prior, MT Works2 versions 1.167Z and prior, MX Component versions 5.001B and prior, Network Interface Board CC IE Control utility versions 1.29F and prior, Network Interface Board CC IE Field Utility versions 1.16S and prior, Network Interface Board CC-Link Ver.2 Utility versions 1.23Z and prior, Network Interface Board MNETH utility versions 34L and prior, PX Developer versions 1.53F and prior, RT ToolBox2 versions 3.73B and prior, RT ToolBox3 versions 1.82L and prior, Setting/monitoring tools for the C Controller module (SW4PVC-CCPU) versions 4.12N and prior, and SLMP Data Collector versions 1.04E and prior) allows a remote unauthenticated attacker to cause a DoS condition on the software products, and possibly to execute a malicious code on the personal computer running the software products although it has not been reproduced, by spoofing MELSEC, GOT or FREQROL and returning crafted reply packets.
Technical Analysis
CVE-2021-20588 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (6)
Quick Facts
Related CVEs (CWE-130)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-20588 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts