hacktricks/pentesting-web/registration-vulnerabilities.md

Registration Vulnerabilities

Takeover

Duplicate Registration

• Try to generate using an existing username
• Check varying the email:
  • uppsercase
  • +1@
  • add some some in the email
  • special characters in the email name %00, %09, %20
  • Put black characters after the email: test@test.com a
  • victim@gmail.com@attacker.com
  • victim@attacker.com@gmail.com

Username Enumeration

Check if you can figure out when a username has already been registered inside the application.

Password Policy

Creating a user check the password policy check if you can use weak passwords.
In that case you may try to bruteforce credentials.

SQL Injection

****Check this page to learn how to attempt account takeovers or extract information via SQL Injections in registry forms.

Oauth Takeovers

{% page-ref page="oauth-to-account-takeover.md" %}

SAML Vulnerabilities

{% page-ref page="saml-attacks/" %}

Change Email

when registered try to change the email and check if this change is correctly validated or can change it to arbitrary emails.

More Checks

• Check if you can use disposable emails
• Long password >200 leads to DoS
• Check rate limits on account creation
• Use username@burp_collab.net and analyze the callback