I will give you a description of vulnerability. You should extract vulnerable functions. Write the output in following format: 
FUNCS function1, ...
If you found no functions, output "NONE"

Here is the description:
A improper restriction of excessive authentication attempts vulnerability [CWE-307] in Fortinet FortiMail version 6.4.0, version 6.2.0 through 6.2.4 and before 6.0.9 allows  a remote unauthenticated attacker to partially exhaust CPU and memory via sending numerous HTTP requests to the login form.
