What’s Vulnerable › Vulnerabilities

CVE-2020-5666

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 8.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-11-16 · updated 2026-06-17
• Weakness: CWE-400

Description

Uncontrolled resource consumption vulnerability in MELSEC iQ-R Series CPU Modules (R00/01/02CPU Firmware versions from '05' to '19' and R04/08/16/32/120(EN)CPU Firmware versions from '35' to '51') allows a remote attacker to cause an error in a CPU unit via a specially crafted HTTP packet, which may lead to a denial-of-service (DoS) condition in execution of the program and its communication.

Affected products

• Mitsubishielectric Melsec Iq-R00 Firmware: from 05 through 19
• Mitsubishielectric Melsec Iq-R01 Firmware: from 05 through 19
• Mitsubishielectric Melsec Iq-R02 Firmware: from 05 through 19
• Mitsubishielectric Melsec Iq-R04 Firmware: from 35 through 51
• Mitsubishielectric Melsec Iq-R08 Firmware: from 35 through 51
• Mitsubishielectric Melsec Iq-R120 Firmware: from 35 through 51
• Mitsubishielectric Melsec Iq-R16 Firmware: from 35 through 51
• Mitsubishielectric Melsec Iq-R32 Firmware: from 35 through 51

References

• https://jvn.jp/en/jp/JVN44764844/index.html
• https://jvn.jp/jp/JVN44764844/index.html
• https://us-cert.cisa.gov/ics/advisories/icsa-20-317-01
• https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2020-015_en.pdf
• https://jvn.jp/en/jp/JVN44764844/index.html
• https://jvn.jp/jp/JVN44764844/index.html
• https://us-cert.cisa.gov/ics/advisories/icsa-20-317-01
• https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2020-015_en.pdf

Get alerted when CVE-2020-5666 or the next vulnerability affects your stack