Vulnerability identifier: #VU57377

Vulnerability risk: High

CVSSv3.1: 8.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:U/RC:C]

CVE-ID: CVE-2021-20599

CWE-ID: CWE-639

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MELSEC iQ-R 08 SFCPU
Hardware solutions / Firmware
MELSEC iQ-R 16 SFCPU
Hardware solutions / Firmware
MELSEC iQ-R 32 SFCPU
Hardware solutions / Firmware
MELSEC iQ-R 120 SFCPU
Hardware solutions / Firmware
MELSEC iQ-R 08 PSFCPU
Hardware solutions / Firmware
MELSEC iQ-R 16 PSFCPU
Hardware solutions / Firmware
MELSEC iQ-R 32 PSFCPU
Hardware solutions / Firmware
MELSEC iQ-R 120 PSFCPU
Hardware solutions / Firmware

Vendor: Mitsubishi Electric

Description

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.

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

Vulnerable software versions

MELSEC iQ-R 08 SFCPU: All versions

MELSEC iQ-R 16 SFCPU: All versions

MELSEC iQ-R 32 SFCPU: All versions

MELSEC iQ-R 120 SFCPU: All versions

MELSEC iQ-R 08 PSFCPU: All versions

MELSEC iQ-R 16 PSFCPU: All versions

MELSEC iQ-R 32 PSFCPU: All versions

MELSEC iQ-R 120 PSFCPU: All versions

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

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.