Security readout for executives and security teams
Plain-English summary
This flaw affects Honeywell Experion PKS C200, C200E, C300, and ACE controllers. A remote unauthenticated attacker may be able to upload a dangerous file, run arbitrary code, and disrupt controller availability. For industrial environments, that can become an operational safety and production continuity issue, not just an IT issue.
Executive priority
Treat this as high-priority for any site operating the affected Honeywell controllers. It has maximum CVSS severity and could affect process availability, but the provided evidence does not confirm active exploitation. Prioritize asset confirmation and vendor-guided remediation before emergency disruption to operations.
Technical view
CVE-2021-38397 is CWE-434 unrestricted upload of a file with dangerous type in listed Honeywell Experion PKS controllers. The CVSS 3.1 score is 10.0 with network attack vector, low complexity, no privileges, no user interaction, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to organizations using the named Honeywell Experion PKS C200, C200E, C300, or ACE controllers. Risk is highest where controller or engineering interfaces are reachable from untrusted networks. The provided sources do not identify exact vulnerable firmware versions, exposed ports, or deployment prevalence.
Exploitation context
The source bundle says this CVE is not in CISA KEV and provides no evidence of active exploitation. The risk remains serious because the CVSS vector describes unauthenticated remote exploitation with low complexity and potential code execution or denial of service.
Researcher notes
The evidence supports critical severity, affected product families, CWE-434, and potential remote code execution plus denial of service. It does not provide exploit details, vulnerable firmware ranges, or a confirmed patch level in the supplied text. Avoid assuming broader Experion products are affected.
Mitigation direction
- Review Honeywell notification SN2021-02-22-01 and CISA ICSA-21-278-04 for vendor-approved remediation.
- Inventory Experion PKS C200, C200E, C300, and ACE controller deployments.
- Restrict controller and engineering access to trusted management networks only.
- Prioritize remediation for internet-exposed or third-party-accessible control environments.
- Use vendor guidance for patches, configuration changes, or compensating controls.
Validation and detection
- Confirm whether any listed Honeywell controller models are deployed.
- Map reachable management, engineering, and controller interfaces for those assets.
- Check current firmware and configuration against Honeywell and CISA guidance.
- Review access paths from corporate, remote-access, and vendor-support networks.
- Monitor affected environments for unexpected uploads, crashes, or controller instability.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-38397 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H3.96Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.