Authorization bypass through user-controlled key in Mitsubishi Electric products - CVE-2021-20599

Vulnerability identifier: #VU57377

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-20599

CWE-ID: CWE-639

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exist due to insufficient access authorization. A remote attacker can log in to the CPU module by obtaining credentials other than password.

MELSEC iQ-R 08 SFCPU
MELSEC iQ-R 16 SFCPU
MELSEC iQ-R 32 SFCPU
MELSEC iQ-R 120 SFCPU
MELSEC iQ-R 08 PSFCPU
MELSEC iQ-R 16 PSFCPU
MELSEC iQ-R 32 PSFCPU
MELSEC iQ-R 120 PSFCPU

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

• https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-011_en.pdf
• https://us-cert.cisa.gov/ics/advisories/icsa-21-287-03

• Authorization bypass through user-controlled key in Mitsubishi Electric MELSEC iQ-R Series