Security readout for executives and security teams
Plain-English summary
CVE-2021-42706 is a high-severity use-after-free vulnerability reported for Advantech HMI Designer/WebAccess MHI Designer. The source bundle says it could disclose information and execute arbitrary code. The CVSS vector indicates local access and user interaction are required, but successful exploitation could compromise confidentiality, integrity, and availability.
Executive priority
Treat this as a high-priority industrial workstation risk where the software is present. It is not KEV-listed in the provided data, but potential arbitrary code execution and all-version exposure justify timely inventory, vendor-guidance review, and remediation tracking.
Technical view
The vulnerability is classified as CWE-416, use after free, with CVSS 3.1 score 7.8. It is assessed as local, low complexity, no privileges required, user interaction required, and high impact across confidentiality, integrity, and availability. The bundle lists Advantech HMI Designer as affected in all versions.
Likely exposure
Organizations using Advantech HMI Designer or WebAccess/MHI Designer should assume possible exposure, especially on engineering or operator workstations. The provided bundle lists all versions affected but does not identify specific fixed versions, deployment prerequisites, or vulnerable file types.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle. No cited source in the bundle states active exploitation. The CVSS vector suggests exploitation requires local access and user interaction, which lowers wormability but still creates serious workstation compromise risk.
Researcher notes
Evidence is limited to the source bundle. The title references AzeoTech DAQFactory, while the affected product and description reference Advantech HMI Designer/WebAccess MHI Designer. Validate product mapping against the CVE and CISA advisory before broad conclusions.
Mitigation direction
- Check the CISA ICS advisory and vendor guidance for supported updates or mitigations.
- Inventory all HMI Designer/WebAccess MHI Designer installations and owners.
- Prioritize remediation for engineering workstations handling external or shared project files.
- Limit local access to affected systems until vendor guidance is applied.
- Review security monitoring for unexpected process behavior on affected workstations.
Validation and detection
- Confirm whether Advantech HMI Designer or WebAccess/MHI Designer is installed.
- Record installed versions and compare them with vendor or CISA advisory guidance.
- Verify whether affected workstations process files from external or untrusted sources.
- Check whether compensating access controls are enforced on engineering workstations.
- Document remediation status and exceptions for each affected installation.
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-416: 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-2021-42706 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
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.