CVE-2020-13417: 
NixOS vulnerability analysis and mitigation

An Elevation of Privilege issue was discovered in Aviatrix VPN Client before version 2.10.7, which was identified as an incomplete fix for CVE-2020-7224. The vulnerability affects Linux, macOS, and Windows installations specifically related to certain OpenSSL parameters. The issue was disclosed on May 22, 2020, and received a CVSS score of 7.5, indicating high severity (CISA Bulletin).

The vulnerability exists in the VPN service where dangerous OpenSSL parameters could lead to unauthorized code execution. This was a follow-up to a previous vulnerability (CVE-2020-7224) where the initial fix was found to be incomplete. The issue specifically relates to how the client handles OpenSSL parameters that could be altered from their issued value set (Aviatrix Docs).

The vulnerability could allow unauthorized code execution through dangerous OpenSSL parameters that are not properly authorized. This affects installations across multiple operating systems including macOS, Linux, and Windows, potentially enabling elevation of privilege attacks (Aviatrix Docs).

The vulnerability requires local access to exploit and involves manipulation of OpenSSL parameters. It was rated with a high severity CVSS score of 7.5, indicating significant potential for exploitation (CISA Bulletin).

The vulnerability was addressed by upgrading to Aviatrix VPN Client version 2.10.7 or later. Additionally, administrators must configure OpenVPN minimum client version to 2.10.7 in the Controller. For complete protection, it's recommended to upgrade both the Client VPN to version 2.10.7 and the Controller & Gateway to version 5.3 or later (Aviatrix Docs).

The vulnerability was responsibly disclosed by Rich Mirch, Senior Adversarial Engineer - TeamARES from Critical Start, Inc., demonstrating active security research in the VPN client space (Aviatrix Docs).