Improper Certificate Validation
An issue was discovered in Docker Moby before 17.06.0. The Docker engine validated a client TLS certificate using both the configured client CA root certificate and all system roots on non-Windows systems. This allowed a client with any domain validated certificate signed by a system-trusted root CA (as opposed to one signed by the configured CA root certificate) to authenticate.
CWE-295 - Improper Certificate Validation
The authenticity component of a web system stems from the ability to validate “Digital certificates”, which (i) establish trust between two or more entities sharing data over a network; (ii) ensure data at rest and transit is secure from unauthorized access; and (iii) check the identity of the actors that interact with the system. An application with absent or ineffective certificate validation mechanisms allows malicious users, impersonating trusted hosts, to manipulate the communication path between the client and the host, resulting in unauthorized access to data and to the application’s internal environment, and potentially enabling man-in-the-middle attacks.