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NVD / CVE Program· CNA Mitsubishi

CVE-2021-20586: Resource management errors vulnerability in a robot controller of MELFA FR Series(controller "CR800-*V*D" of RV-*FR***-D-* all versions, con

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.8% (FIRST EPSS); higher than 86.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Resource management errors vulnerability in a robot controller of MELFA FR Series(controller "CR800-*V*D" of RV-*FR***-D-* all versions, controller "CR800-*HD" of RH-*FRH***-D-* all versions, controller "CR800-*HRD" of RH-*FRHR***-D-* all versions, controller "CR800-*V*R with R16RTCPU" of RV-*FR***-R-* all versions, controller "CR800-*HR with R16RTCPU" of RH-*FRH***-R-* all versions, controller "CR800-*HRR with R16RTCPU" of RH-*FRHR***-R-* all versions, controller "CR800-*V*Q with Q172DSRCPU" of RV-*FR***-Q-* all versions, controller "CR800-*HQ with Q172DSRCPU" of RH-*FRH***-Q-* all versions, controller "CR800-*HRQ with Q172DSRCPU" of RH-*FRHR***-Q-* all versions) and a robot controller of MELFA CR Series(controller "CR800-CVD" of RV-8CRL-D-* all versions, controller "CR800-CHD" of RH-*CRH**-D-* all versions) as well as a cooperative robot ASSISTA(controller "CR800-05VD" of RV-5AS-D-* all versions) allows a remote unauthenticated attacker to cause a DoS of the execution of the robot program and the Ethernet communication by sending a large amount of packets in burst over a short period of time. As a result of DoS, an error may occur. A reset is required to recover it if the error occurs.

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Jan 29, 2021
Updated
Jun 16, 2026
EPSS
2.8% · 86th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.8%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-20586

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
mitsubishielectricrv2fr firmware
mitsubishielectricrv2fr
mitsubishielectricrv2frl firmware
mitsubishielectricrv2frl
mitsubishielectricrv4fr firmware
mitsubishielectricrv4fr
mitsubishielectricrv4frl firmware
mitsubishielectricrv4frl
mitsubishielectricrv7fr firmware
mitsubishielectricrv7fr
mitsubishielectricrv7frl firmware
mitsubishielectricrv7frl

and 54 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • mitsubishielectric rh12frh55 firmwareall versions
  • mitsubishielectric rh12frh85 firmwareall versions
  • mitsubishielectric rh12rfh70 firmwareall versions
  • mitsubishielectric rh1frhr firmwareall versions
  • mitsubishielectric rh20frh100 firmwareall versions
  • mitsubishielectric rh20frh85 firmwareall versions
  • mitsubishielectric rh3frh35 firmwareall versions
  • mitsubishielectric rh3frh45 firmwareall versions
  • mitsubishielectric rh3frh55 firmwareall versions
  • mitsubishielectric rh3frhr firmwareall versions
  • mitsubishielectric rh6frh35 firmwareall versions
  • mitsubishielectric rh6frh45 firmwareall versions
  • mitsubishielectric rh6frh55 firmwareall versions
  • mitsubishielectric rv13fr firmwareall versions
  • mitsubishielectric rv13frl firmwareall versions
  • mitsubishielectric rv13frlm/c firmwareall versions
  • mitsubishielectric rv13frm/c firmwareall versions
  • mitsubishielectric rv20fr firmwareall versions
  • mitsubishielectric rv20frm/c firmwareall versions
  • mitsubishielectric rv2fr firmwareall versions

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Mitsubishi). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a Robot Controller MELFA FR Series; Robot Controller CR Series; Cooperative Robot ASSISTA

    • Controller "CR800-*V*D" of RV-*FR***-D-* all versions, Controller "CR800-*HD" of RH-*FRH***-D-* all versions, Controller "CR800-*HRD" of RH-*FRHR***-D-* all versions, Controller "CR800-*V*R with R16RT, Controller "CR800-CVD" of RV-8CRL-D-* all versions, Controller "CR800-CHD" of RH-*CRH**-D-* all versions, Controller "CR800-05VD" of RV-5AS-D-* all versionsaffected

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records