A path traversal vulnerability exists in the Leadsec SSL VPN (formerly Lenovo NetGuard), allowing unauthenticated attackers to read arbitrary files on the underlying system via the ostype parameter in the /vpn/user/download/client endpoint. This flaw arises from insufficient input sanitation, enabling traversal sequences to escape the intended directory and access sensitive files. Exploitation evidence was observed by the Shadowserver Foundation on 2025-02-10 UTC.
