A. XSS could be used to inject code into the login page during the redirect to the HTTPS site. The consultant should implement a WAF to prevent this.

B. The consultant is concerned the site is using an older version of the SSL 3.0 protocol that is vulnerable to a variety of attacks. Upgrading the site to TLS 1.0 would mitigate this issue.

C. The HTTP traffic is vulnerable to network sniffing, which could disclose usernames and passwords to an attacker. The consultant should recommend disabling HTTP on the web server.

D. A successful MITM attack Could intercept the redirect and use sslstrip to decrypt further HTTPS traffic. Implementing HSTS on the web server would prevent this.