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Fencer Intel
high 7.5

CVE-2021-20594 json

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Mitsubishi Electric MELSEC iQ-R series Safety CPU modules R08/1…

published 5y ago modified 4mo ago also EUVD-2021-8012

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.4%
EPSS 2.4% chance of exploitation in 30 days, percentile 83%
public exploits
0
none known

Summary

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Mitsubishi Electric MELSEC iQ-R series Safety CPU modules R08/16/32/120SFCPU firmware versions "26" and prior and Mitsubishi Electric MELSEC iQ-R series SIL2 Process CPU modules R08/16/32/120PSFCPU firmware versions "11" and prior allows a remote unauthenticated attacker to acquire legitimate user names registered in the module via brute-force attack on user names.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-250-01 updated cvss 5.9

Mitsubishi Electric MELSEC iQ-R Series

  • Mitsubishi Electric Corporation MELSEC iQ-R series Safety CPU R08SFCPU Firmware <=26 Mitsubishi Electric Corporation MELSEC iQ-R series Safety CPU R16SFCPU Firmware <=26 Mitsubishi Electric Corporation MELSEC iQ-R series Safety CPU R32SFCPU Firmware <=26 Mitsubishi Electric Corporation MELSEC iQ-R series Safety CPU R120SFCPU Firmware <=26 Mitsubishi Electric Corporation MELSEC iQ-R series SIL2 Process CPU R08PSFCPU Firmware <=11 Mitsubishi Electric Corporation MELSEC iQ-R series SIL2 Process CPU R16PSFCPU Firmware <=11
    +2 more products
    Mitsubishi Electric Corporation MELSEC iQ-R series SIL2 Process CPU R32PSFCPU Firmware <=11 Mitsubishi Electric Corporation MELSEC iQ-R series SIL2 Process CPU R120PSFCPU Firmware <=11
    affected: mitigation “MELSEC iQ-R series Safety CPU R08/16/32/120SFCPU:Firmware versions "27" or later” mitsubishifa.co.th

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

2.37% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • n/a Mitsubishi Electric MELSEC iQ-R series Safety CPU modules R08/16/32/120SFCPU; Mitsubishi Electric MELSEC iQ-R series SIL2 Process CPU modules R08/16/32/120PSFCPU

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.