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Fencer Vulns
critical 10.0

CVE-2021-38397 json

Honeywell Experion PKS and ACE Controllers Unrestricted Upload of File with Dangerous Type

published 2022-10-28 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-24849

cvss
10.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 67%
public exploits
0
none known

Summary

Honeywell Experion PKS C200, C200E, C300, and ACE controllers are vulnerable to unrestricted file uploads, which may allow an attacker to remotely execute arbitrary code and cause a denial-of-service condition.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-278-04 updated cvss 10.0

Honeywell Experion PKS and ACE Controllers

  • Honeywell C200 Honeywell C200E Honeywell C300 and ACE controllers
    affected: mitigation “Honeywell recommends users follow all guidance in the Experion Network and Security Planning Guide to prevent attacks by malicious actors.” honeywellprocess.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
18 mo ago

Exploit prediction

1.18% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
NVD 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Honeywell Experion PKS

Classification

Weakness
  • CWE-434 Unrestricted Upload of File with Dangerous Type

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.