How severe is CVE-2021-38397?

CVE-2021-38397 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-38397 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38397?

CVE-2021-38397 primarily affects Honeywell C200 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-38397?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-38397 published?

CVE-2021-38397 was published on 2022-10-28 and last updated on 2026-06-17.

CVE-2021-38397

CVE-2021-38397 is a critical-severity vulnerability in Honeywell C200 Firmware with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-434.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Honeywell C200 Firmware
Published: 2022-10-28
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-38397?: 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.
How severe is CVE-2021-38397?: CVE-2021-38397 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-38397 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38397?: CVE-2021-38397 primarily affects Honeywell C200 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-38397?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-38397 published?: CVE-2021-38397 was published on 2022-10-28 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:honeywell:c200_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:c200e_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:c300_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:application_control_environment_firmware:-:*:*:*:*:*:*:*

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