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

Vulnerability identifier: #VU56391

CSH Severity: Low

CVSSv4.0: 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: Remote access

Exploit availability: No public exploit available

Vulnerable software:
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

Software vendor:
Mitsubishi Electric

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.

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

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