CVE-2021-20611

No known exploitation. EPSS puts it in the 88th percentile. A vendor fix is available.

CVSS 3.17.5High EPSS percentile88th3.2% chance in 30 days CISA KEVNot listedNo confirmed exploitation
No public exploit known FixVendor fixNo build named by the sources

Published 2021-12-01Updated 2024-11-21Sources: CVE.org, NVD, BDU, CSAF

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

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What it is

From the CVE record

Improper Input Validation vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS88th

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

3.2% chance of exploitation activity in the next 30 days, which ranks it in the 88th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

5 events over 1086 days, from the signal feeds we watch.

2024-11-21Patch availablerecord updated
2021-12-01Publishedweakness classified, att&ck mapped

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Scored 7.5 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required NoneNo authentication required — anyone can exploit this
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality NoneNo confidentiality impact
Integrity NoneNo integrity impact
Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

CWE-20No name in the record

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Initial AccessT1190Exploit Public-Facing Applicationlow confidence

Sources

References in the record

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