CVE-2021-20598 Denial of service in MELSEC iQ-R series CPU modules R08/16/32/120SFCPU; R08/16/32/120PSFCPU

Medium 5.3 Published 6 Aug 2021 Updated 3 Aug 2024

Remote attackers can lock out legitimate users by repeatedly attempting incorrect logins, causing denial of service on Mitsubishi MELSEC iQ-R CPU modules.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-20598?

CVE-2021-20598 is a medium-severity denial of service vulnerability in MELSEC iQ-R series CPU modules R08/16/32/120SFCPU; R08/16/32/120PSFCPU, published on 6 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Overly Restrictive Account Lockout Mechanism vulnerability in Mitsubishi Electric MELSEC iQ-R series CPU modules (R08/16/32/120SFCPU all versions, R08/16/32/120PSFCPU all versions) allows a remote unauthenticated attacker to lockout a legitimate user by continuously trying login with incorrect password.

Weakness: CWE-287

Which versions are affected by CVE-2021-20598?

It affects 8 products.

Products include Mitsubishielectric R08psfcpu Firmware, Mitsubishielectric R08sfcpu Firmware, Mitsubishielectric R120psfcpu Firmware, Mitsubishielectric R120sfcpu Firmware, Mitsubishielectric R16psfcpu Firmware, Mitsubishielectric R16sfcpu Firmware and 2 more.

How do I fix CVE-2021-20598?

No fix has been published for CVE-2021-20598 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-20598 being exploited?

There is no known exploitation of CVE-2021-20598 in the wild and no public exploit code.

Sources

Also known as GHSA-f5j9-pg8j-928p.