OAUTH MISCONFIGURATION

Description:
Hello Team,
OAUTH is a functionality used by a user for easy sign up or login on your domain. 
In this account attacker can easily control victim’s account, if victim uses OAUTH functionality.

Replication Steps:

(ATTACKER PHASE)

1.Make an account with victim’s email address and set password.
2.Now you have access to victim’s account through password and email id .

(VICTIM COMES )

3.Victim will create account through google OAuth functionality.
4.Thus, victim is not required to set password.

(EXPLOIT)

5.You can access victims account through password you set in attacker phase.
6.So, you can use victim account whenever you want!

MITIGATION:
-Allow only OAuth sign up or Email address Sign up.
-I have attached PoC for your ready reference.

Thank you