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NVD / CVE Program· CNA schneider

CVE-2021-22816: A CWE-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists that could cause a Denial of Service of the RTU when re

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: 0.94% (FIRST EPSS); higher than 61.3% 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-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists that could cause a Denial of Service of the RTU when receiving a specially crafted request over Modbus, and the RTU is configured as a Modbus server. Affected Products: SCADAPack 312E, 313E, 314E, 330E, 333E, 334E, 337E, 350E and 357E RTUs with firmware V8.18.1 and prior

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Jan 28, 2022
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%

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-2021-22816

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
schneider-electricscadapack 312e firmware
schneider-electricscadapack 312e
schneider-electricscadapack 313e firmware
schneider-electricscadapack 313e
schneider-electricscadapack 314e firmware
schneider-electricscadapack 314e
schneider-electricscadapack 330e firmware
schneider-electricscadapack 330e
schneider-electricscadapack 333e firmware
schneider-electricscadapack 333e
schneider-electricscadapack 334e firmware
schneider-electricscadapack 334e

and 6 more

Affected versions

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

  • schneider-electric scadapack 312e firmwarebefore 8.19.1
  • schneider-electric scadapack 313e firmwarebefore 8.19.1
  • schneider-electric scadapack 314e firmwarebefore 8.19.1
  • schneider-electric scadapack 330e firmwarebefore 8.19.1
  • schneider-electric scadapack 333e firmwarebefore 8.19.1
  • schneider-electric scadapack 334e firmwarebefore 8.19.1
  • schneider-electric scadapack 337e firmwarebefore 8.19.1
  • schneider-electric scadapack 350e firmwarebefore 8.19.1
  • schneider-electric scadapack 357e firmwarebefore 8.19.1

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)

CWE-754 · Improper Check for Unusual or Exceptional Conditions

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