Security readout for executives and security teams
Plain-English summary
CVE-2021-33004 affects WebAccess HMI Designer 2.1.9.95 and earlier. A specially crafted user-supplied file can trigger memory corruption and may allow arbitrary code execution. The important limiter is that a user must interact with the file in HMI Designer.
Executive priority
Treat this as high priority where affected Designer systems handle external files or support operational environments. The business risk is code execution on engineering workstations, but urgency is moderated by required user interaction and no confirmed active exploitation in the provided bundle.
Technical view
The issue is a CWE-119 memory corruption flaw caused by insufficient validation of user-supplied files in WebAccess HMI Designer. The CVE states arbitrary code execution may be possible, but the provided bundle contains no CVSS vector, patch details, or exploit mechanics.
Likely exposure
Exposure is most likely on engineering or OT workstations where WebAccess HMI Designer 2.1.9.95 or earlier is installed and users open imported or externally supplied HMI files. This is not described as a network-only vulnerability in the provided sources.
Exploitation context
The provided sources say user interaction is required. CISA KEV status is false in the bundle, and no cited source states active exploitation. Exploitation risk depends on getting a target user to open a malicious or malformed file in the affected Designer application.
Researcher notes
The bundle provides a concise CVE description and CISA ICS advisory reference, but no CVSS, exploit status, vendor patch version, or detailed remediation text. Avoid assuming broader WebAccess product impact beyond WebAccess HMI Designer versions 2.1.9.95 and prior.
Mitigation direction
- Inventory WebAccess HMI Designer installations and identify versions 2.1.9.95 or earlier.
- Check the CISA advisory and vendor guidance for fixed versions or supported mitigations.
- Limit use of affected Designer systems to trusted project files only.
- Restrict email, web, and removable-media file intake on engineering workstations.
- Use endpoint controls to contain Designer process abuse where feasible.
Validation and detection
- Confirm whether WebAccess HMI Designer is installed on engineering and OT support systems.
- Record exact product versions and compare them with 2.1.9.95 and earlier.
- Review workflows where users import or open third-party HMI files.
- Check endpoint logs for crashes or unusual Designer child processes after file opens.
- Verify vendor guidance has been reviewed before declaring remediation complete.
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-119: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2021-33004 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://us-cert.cisa.gov/ics/advisories/icsa-21-173-01CVE reference · x_refsource_MISC
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.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.