> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/web/oauth-authentication/forced-oauth-profile-linking.md).
# Forced OAuth Profile Linking
Forced OAuth Profile Linking notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context.
### JForced OAuth Profile Linking
**Description of lab**
This lab offers a functionality to link a social network profile to a user account to connect via OAuth instead of using traditional authentication. / Due to an unsecured implementation of the client-side OAuth stream, an attacker can divert this mechanism to associate its own social profile with another user's account.
Objective:/ Conduct a CSRF attack to link your social network profile to the site administrator account, then access the admin panel and delete user **carlos**.
Contraintes :
* The administrator systematically opens any content sent from the operating server.
* The administrator always has an active session on the blog site.
**Comptes disponibles**
* Site account: `wiener / peter`
* Social network profile: `peter.wiener / hotdog`
**Analysis of the OAuth mechanism**
* The site allows a classic connection via login and password.
A connection via OAuth (social network) is also available.
* An existing user can link a social network profile to his or her account.
During the link, an OAuth query is sent to the authentication point:
{% code overflow="wrap" %}
```http
GET /auth?client_id=s4z8vs36ubaet908r8qfn&redirect_uri=https://0ac30047040d749984bf3b740088002a.web-security-academy.net/oauth-linking&response_type=code&scope=openid%20profile%20email HTTP/2
```
{% endcode %}
After authentication, the user is redirected to a URL containing an OAuth code:
```http
GET /oauth-linking?code=pYNeIWIFHaUh_fmTub7fAYLzcyNAEvDoKMh9iljTU1Q HTTP/2
```
This code:
* Is for single use
* To link the OAuth profile to the currently authenticated account
**Exploitation of vulnerability**
1. Start the link procedure between your account and your social network profile.
2. Intercept and copy the `/OAuth-linking?code=...` URL.
Drop the request so that the code is not consumed.
From the operating server, send this URL to the administrator via a CSRF attack, for example using an iframe
{% code overflow="wrap" %}
```javascript
```
{% endcode %}
The administrator loads the page:
OAuth code is consumed
The attacker's OAuth profile is linked to the administrator account
---
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