VitaFit Android application (com.vt.vitafit) before 2.8.1.0 contains an insecure TLS/SSL certificate validation vulnerability that allows network-based attackers to intercept and modify HTTPS traffic by exploiting a custom X509TrustManager that trusts all certificates and a hostname verifier that accepts any hostname. Attackers can perform a man-in-the-middle attack to capture account sessions and health-related API data, and use a captured session to delete the account's authentication record and prevent legitimate login.