Improper Certificate Validation
It was discovered evolution-ews before 3.31.3 does not check the validity of SSL certificates. An attacker could abuse this flaw to get confidential information by tricking the user into connecting to a fake server without the user noticing the difference.
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.