Security readout for executives and security teams
Plain-English summary
CVE-2021-46634 is a high-impact file parsing flaw in Bentley MicroStation CONNECT 10.16.0.80. A user must open a malicious JT file or visit a malicious page. Successful exploitation could run attacker code with the user’s privileges, threatening design workstations and project data.
Executive priority
Treat as high priority for organizations using MicroStation in production design environments. The vulnerability is not described as remotely exploitable without user action, but a single malicious model file could compromise valuable engineering workstations and project data.
Technical view
The flaw is a CWE-787 out-of-bounds write in JT file parsing. Crafted JT data can write past an allocated buffer and allow arbitrary code execution in the current MicroStation process. CVSS is 7.8, reflecting user interaction but high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on engineering, architecture, CAD, or design endpoints running Bentley MicroStation CONNECT 10.16.0.80, especially where users receive JT or model files from external parties.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires user interaction: opening a malicious file or visiting a malicious page. That makes phishing, supplier file exchange, and project collaboration channels the main risk paths.
Researcher notes
ZDI tracks this as ZDI-CAN-15464 and describes arbitrary code execution via crafted JT parsing. The source bundle identifies one affected version only: MicroStation CONNECT 10.16.0.80. Patch details are not included in the supplied text, so defer to Bentley guidance.
Mitigation direction
- Inventory endpoints for Bentley MicroStation CONNECT 10.16.0.80.
- Check Bentley advisory BE-2021-0005 for fixed versions or vendor workarounds.
- Restrict opening JT files from untrusted or unsolicited sources.
- Route external CAD files through malware scanning and trusted exchange workflows.
- Limit MicroStation execution privileges where operationally practical.
Validation and detection
- Confirm whether MicroStation CONNECT 10.16.0.80 is installed on any managed endpoint.
- Review file association and workflow exposure for JT files.
- Verify Bentley vendor guidance has been applied where affected installs exist.
- Check security telemetry for unusual MicroStation crashes or suspicious child processes.
- Confirm users handling external CAD files know the trusted intake process.
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
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CWE-787: Exact CWE lookup
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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-2021-46634 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/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:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.8HighVector: CVSS:3.0/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.bentley.com/en/common-vulnerability-exposure/BE-2021-0005CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-22-221/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.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.