Security readout for executives and security teams
Plain-English summary
This is a high-impact flaw in WECON LeviStudioU, an engineering tool. A malicious file or local interaction could trigger a stack buffer overflow and allow code execution on the workstation. The main business concern is compromise of systems used to build or maintain industrial HMI projects.
Executive priority
Treat this as a priority for OT engineering environments, not broad enterprise internet exposure. The business risk is workstation compromise leading to tampering, credential theft, or disruption around HMI project workflows. Remediation urgency is higher where engineers exchange project files externally.
Technical view
CVE-2021-23138 is a CWE-121 stack-based buffer overflow affecting WECON LeviStudioU versions 2019-09-21 and prior. CVSS 3.1 is 7.8 with local attack vector, low complexity, no privileges, and required user interaction. Successful exploitation may allow code execution with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on engineering workstations where LeviStudioU is installed, especially where users open project files from email, shared drives, vendors, or contractors. The provided data does not indicate a network-facing service exposure.
Exploitation context
The source bundle marks CISA KEV as false and provides no evidence of active exploitation. Public CISA and ZDI advisories exist. The CVSS vector requires local access and user interaction, so realistic exploitation depends on convincing a user to open or process malicious content.
Researcher notes
The bundle identifies the affected product and CVSS vector but does not include a named fixed version or detailed vulnerable file parser. Avoid assuming broad remote reachability. Focus validation on installed versions, user interaction paths, and endpoint behavior around LeviStudioU.
Mitigation direction
- Inventory all workstations for WECON LeviStudioU installations.
- Check CISA and WECON guidance for fixed versions or vendor mitigations.
- Remove or restrict affected LeviStudioU versions where not operationally required.
- Block untrusted LeviStudioU project files from email and shared transfer paths.
- Harden engineering workstations with least privilege and endpoint monitoring.
Validation and detection
- Confirm whether LeviStudioU 2019-09-21 or earlier is installed.
- Review software inventory for unmanaged engineering laptops and contractor machines.
- Check endpoint telemetry for suspicious child processes from LeviStudioU.
- Verify users cannot open project files from untrusted sources without controls.
- Track the CVE in vulnerability management until vendor guidance is applied.
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-121: 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 lookupCVE-2021-23138 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://www.cisa.gov/uscert/ics/advisories/icsa-21-355-03CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-133/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-139/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-134/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-136/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-138/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-141/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-137/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-131/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-135/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-142/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-129/CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-140/CVE 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.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.