CVE-2021-27494: 
Homebrew vulnerability analysis and mitigation

CVE-2021-27494 is a stack-based buffer overflow vulnerability affecting Datakit Software libraries (CatiaV5_3dRead, CatiaV6_3dRead, Step3dRead, Ug3dReadPsr, Jt3dReadPsr modules) in KeyShot Versions v10.1 and prior. The vulnerability was discovered in early 2021 and publicly disclosed on May 25, 2021. The issue stems from improper validation of user-supplied data when parsing STP files (CISA Advisory, ZDI Advisory).

The vulnerability is characterized by a lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer when parsing STP files. This flaw has been assigned a CVSS v3.1 base score of 7.8 (HIGH) with the vector string: AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The vulnerability requires local access and user interaction to exploit (ZDI Advisory, NVD).

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code in the context of the current process. The high CVSS score reflects the potential for complete compromise of system confidentiality, integrity, and availability if successfully exploited (CISA Advisory).

The vulnerability requires user interaction to exploit, specifically the target must visit a malicious page or open a malicious file. There are no known public exploits specifically targeting this vulnerability, and it is not exploitable remotely (CISA Advisory, ZDI Advisory).

Datakit has released CrossCAD/Ware library Version 2021.2 to address this vulnerability. Luxion has released KeyShot v10.2, which includes the updated Datakit libraries. Users are recommended to upgrade to these latest versions. As a workaround, users should avoid opening untrusted files from unknown sources (CISA Advisory).