Vulnerability · Published Jun 11, 2021 · Assigned by Mitsubishi

CVE-2021-20591

High 7.5

In plain English

A high-severity security flaw in MELSEC iQ-R series CPU modules. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.5% (higher than 74% of all known vulnerabilities).

Severity (CVSS NVD)7.5High

Exploit odds (30 days)1.5%top 25.7% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
n/a	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

References

https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-003_en.pdf x_refsource_MISC
https://jvn.jp/vu/JVNVU98060539/index.html x_refsource_MISC