CVE-2021-34904: 
Bentley MicroStation CONNECT vulnerability analysis and mitigation

This vulnerability (CVE-2021-34904) affects Bentley View software and involves a heap-based buffer overflow in DGN file parsing that could lead to remote code execution. The vulnerability was discovered by Mat Powell of Trend Micro Zero Day Initiative and was disclosed on December 8, 2021. The issue affects installations of Bentley View when processing DGN files (ZDI Advisory, Bentley Advisory).

The vulnerability exists within the parsing of DGN files and results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. The vulnerability has been assigned a CVSS v3.1 score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating a high severity issue (ZDI Advisory).

A successful exploit could allow an attacker to execute arbitrary code in the context of the current process. User interaction is required to exploit this vulnerability as the target must visit a malicious page or open a malicious file (ZDI Advisory).

Bentley has issued an update to correct this vulnerability. Users should update to version 10.16.02.* or more recent versions of the software. As a general best practice, it is recommended to only open DGN files coming from trusted sources (Bentley Advisory).