Security readout for executives and security teams
Plain-English summary
CVE-2021-46581 is a 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 let an attacker run code as the current user, creating risk for design workstations handling external CAD or 3D assets.
Executive priority
Treat this as high priority for engineering and design environments using the affected MicroStation version. Business urgency is highest where external model files are common, because compromise could affect sensitive project data and workstation integrity.
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 enable arbitrary code execution within the MicroStation process. The CVSS v3.0 score is 7.8, with user interaction required and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure appears limited to organizations running Bentley MicroStation CONNECT 10.16.0.80, especially users who receive or review JT files from external parties. The source bundle does not identify additional affected versions or products.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires user interaction, such as opening a malicious file or visiting a malicious page, so phishing and file-exchange workflows are the most relevant risk paths.
Researcher notes
The evidence supports a JT parser out-of-bounds write tied to ZDI-CAN-15375 and ZDI-22-168. The bundle names only MicroStation CONNECT 10.16.0.80. Do not broaden affected scope without vendor confirmation. No public exploitation evidence is provided here.
Mitigation direction
- Review Bentley advisory BE-2021-0005 and apply vendor-provided updates or mitigations.
- Prioritize remediation for workstations handling external JT files.
- Restrict opening JT files from untrusted or unexpected sources.
- Use isolated review environments for externally supplied CAD or 3D files.
- Remove or retire MicroStation CONNECT 10.16.0.80 where no longer required.
Validation and detection
- Inventory Bentley MicroStation CONNECT installations and identify version 10.16.0.80.
- Confirm whether affected users process JT files from external sources.
- Check whether Bentley BE-2021-0005 guidance has been applied.
- Review endpoint telemetry for unusual MicroStation crashes or suspicious process activity.
- Verify file-handling controls cover untrusted JT files.
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-787: 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-2021-46581 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-22-168/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.