CVE-2021-20591 Denial of service in MELSEC iQ-R series CPU modules
Remote unauthenticated attackers can cause denial of service on Mitsubishi MELSEC iQ-R CPU modules by exhausting connection resources.
- 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-2021-20591?
CVE-2021-20591 is a high-severity denial of service vulnerability in MELSEC iQ-R series CPU modules, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R series CPU modules (R00/01/02CPU all versions, R04/08/16/32/120(EN)CPU all versions, R08/16/32/120SFCPU all versions, R08/16/32/120PCPU all versions, R08/16/32/120PSFCPU all versions) allows a remote unauthenticated attacker to prevent legitimate clients from connecting to the MELSOFT transmission port (TCP/IP) by not closing a connection properly, which may lead to a denial of service (DoS) condition.
Weakness: CWE-400
Which versions are affected by CVE-2021-20591?
It affects 20 products.
Products include Mitsubishielectric R00cpu Firmware, Mitsubishielectric R01cpu Firmware, Mitsubishielectric R02cpu Firmware, Mitsubishielectric R04cpu Firmware, Mitsubishielectric R08cpu Firmware, Mitsubishielectric R08pcpu Firmware and 14 more.
How do I fix CVE-2021-20591?
No fix has been published for CVE-2021-20591 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-2021-20591 being exploited?
There is no known exploitation of CVE-2021-20591 in the wild and no public exploit code.
Other vulnerabilities in MELSEC iQ-R series CPU modules
Sources
Also known as GHSA-mhpv-hfp2-2648.