CVE-2021-38399

HIGHNVD 7.57.5—

7.5

Honeywell Experion PKS C200, C200E, C300, and ACE controllers are vulnerable to relative path traversal, which may allow an attacker access to unauthorized files and directories.

CVSS v3: 7.5
EG Score: 7.5(medium)
EPSS: 56.0%
KEV: Not listed

Published

October 28, 2022

Last Modified

November 21, 2024

References (4)

ics-cert@hqhttps://www.cisa.gov/uscert/ics/advisories/icsa-21-278-04
ics-cert@hqhttps://www.honeywellprocess.com/library/support/notifications/Customer/SN2021-02-22-01-Experion-C300-CCL.pdf
af854a3a-2127-422b-91ae-364da2661108https://www.cisa.gov/uscert/ics/advisories/icsa-21-278-04
af854a3a-2127-422b-91ae-364da2661108https://www.honeywellprocess.com/library/support/notifications/Customer/SN2021-02-22-01-Experion-C300-CCL.pdf

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 9× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-25 13:04 UTCEG score recompute
2026-05-25 13:04 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-38399?

CVE-2021-38399 is a high vulnerability published on October 28, 2022. Honeywell Experion PKS C200, C200E, C300, and ACE controllers are vulnerable to relative path traversal, which may allow an attacker access to unauthorized files and directories.

When was CVE-2021-38399 disclosed?

CVE-2021-38399 was first published in the National Vulnerability Database on October 28, 2022, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-38399 actively exploited?

CVE-2021-38399 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 56.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-38399?

CVE-2021-38399 has a CVSS v3 base score of 7.5 (NVD).

How do I remediate CVE-2021-38399?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-38399, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-38399

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Is Your Infrastructure Affected by CVE-2021-38399?

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CVE-2021-38399

📅 Published

🔄 Last Modified

🔗 References (4)