Bentley ID: BE-2021-0012
CVE ID: CVE-2021-34886, CVE-2021-46620, CVE-2021-46630
Severity: 3.3
CVSS v3.1: AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Publication date: 2021-12-07
Revision date: 2021-12-07

Summary
MicroStation and MicroStation-based applications may be affected by out-of-bounds read or use-after-free vulnerabilities when opening maliciously crafted FBX files. Exploiting these vulnerabilities could lead to code execution.

Details
The following vulnerabilities related to this advisory were discovered by TrendMicro ZDI: ZDI-CAN-14839, ZDI-CAN-15414, ZDI-CAN-15460. Using an affected version of MicroStation or MicroStation-based application to open a FBX file containing maliciously crafted data can force an out-of-bounds read or use-after-free vulnerability. Exploitation of these vulnerabilities within the parsing of FBX files could enable an attacker to execute arbitrary code in the context of the current process.

Affected Versions

Recommended Mitigations
Bentley recommends updating to the latest versions of MicroStation and MicroStation-based applications. As a general best practice, it is also recommended to only open FBX files coming from trusted sources.

Acknowledgement
Thanks to Mat Powell of Trend Micro Zero Day Initiative for discovering these vulnerabilities.

Revision History