#VU56391 Overly Restrictive Account Lockout Mechanism in Mitsubishi Electric products - CVE-2021-20598

Vulnerability identifier: #VU56391

Vulnerability risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20598

CWE-ID: CWE-645

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 exists due to overly restrictive account lockout mechanism. A remote attacker can lock out a legitimate user by continually attempting to login with a known username and incorrect passwords.

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
https://jvn.jp/vu/JVNVU98578731/index.html
https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-008_en.pdf

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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.