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NVD / CVE Program· CNA schneider

CVE-2021-22792: A CWE-476: NULL Pointer Dereference vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updati

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 0.95% (FIRST EPSS); higher than 61.2% 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

A CWE-476: NULL Pointer Dereference vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file exists in Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions).

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Sep 2, 2021
Updated
Jun 16, 2026
EPSS
0.9% · 61th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.9%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2021-22792

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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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
schneider-electricmodicon m340 bmxp341000
schneider-electricmodicon m340 bmxp342010
schneider-electricmodicon m340 bmxp342020
schneider-electricmodicon m340 bmxp342030
schneider-electricmodicon m580 bmeh582040
schneider-electricmodicon m580 bmeh582040c
schneider-electricmodicon m580 bmeh582040s
schneider-electricmodicon m580 bmeh584040
schneider-electricmodicon m580 bmeh584040c
schneider-electricmodicon m580 bmeh584040s
schneider-electricmodicon m580 bmeh586040
schneider-electricmodicon m580 bmeh586040c

and 37 more

Affected versions

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

  • schneider-electric modicon m340 bmxp341000all versions
  • schneider-electric modicon m340 bmxp342010all versions
  • schneider-electric modicon m340 bmxp342020all versions
  • schneider-electric modicon m340 bmxp342030all versions
  • schneider-electric modicon m580 bmeh582040all versions
  • schneider-electric modicon m580 bmeh582040call versions
  • schneider-electric modicon m580 bmeh582040sall versions
  • schneider-electric modicon m580 bmeh584040all versions
  • schneider-electric modicon m580 bmeh584040call versions
  • schneider-electric modicon m580 bmeh584040sall versions
  • schneider-electric modicon m580 bmeh586040all versions
  • schneider-electric modicon m580 bmeh586040call versions
  • schneider-electric modicon m580 bmeh586040sall versions
  • schneider-electric modicon m580 bmep581020all versions
  • schneider-electric modicon m580 bmep581020hall versions
  • schneider-electric modicon m580 bmep582020all versions
  • schneider-electric modicon m580 bmep582020hall versions
  • schneider-electric modicon m580 bmep582040all versions
  • schneider-electric modicon m580 bmep582040hall versions
  • schneider-electric modicon m580 bmep582040sall versions

Versions reported by the vendor

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

  • n/a Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (

    • Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (affected

Same product

schneider-electric: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-22791A CWE-787: Out-of-bounds Write vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating th
    26Monitor
  • CVE-2021-22790A CWE-125: Out-of-bounds Read vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the
    26Monitor
  • CVE-2021-22789A CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability that could cause a Denial of Service on the
    26Monitor

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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)

CWE-476 · NULL Pointer Dereference

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

Show all references (1 more)

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

All records