updated Oauth Misconfiguration

CVEs/2021/CVE-2021-36873.md

@@ -1,7 +1,7 @@
 # CVE-2021-36873
 
 ## Description
-Authenticated Persistent Cross-Site Scripting (XSS) vulnerability in WordPress iQ Block Country plugin (versions <= 1.2.11). Vulnerable parameter: &blockcountry_blockmessage.
+Authenticated Persistent Cross-Site Scripting (XSS) vulnerability in WordPress iQ Block Country plugin (versions <= 1.2.11). Vulnerable parameter: `&blockcountry_blockmessage`.
 
 ## CVSS (Vector and Score)
 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N - 5.5 MEDIUM
@@ -17,9 +17,14 @@ WordPress iQ Block Country plugin
 
 ## Steps to Reproduce
 1. Login as administrator
-2. 
-
+2. Go to http://localhost/wp-admin/options-general.php?page=iq-block-country%2Flibs%2Fblockcountry-settings.php
+3. Find `Message to display when people are blocked:` form
+4. Input `</textarea><script>alert(1)</script>`
+5. Scroll down and press `Save Changes` button
 
 ## Proof of Concept
-- Image
 - Video
+
+    > https://youtu.be/WtOiHY5R-t0
+- Image
+![image](https://user-images.githubusercontent.com/36522826/202700374-52d36350-adff-4fe3-b46d-21f08955e8c6.png)

OAuth Misconfiguration.md

@@ -4,21 +4,46 @@
 The most infamous OAuth-based vulnerability is when the configuration of the OAuth service itself enables attackers to steal authorization codes or access tokens associated with other users’ accounts. By stealing a valid code or token, the attacker may be able to access the victim's account.
 
 ## Where to find
-In the SSO feature. For example `Log in with google` or `Log in with facebook`.
+In the SSO feature. For example the URL will be looks like this
+```
+https://example/signin?response_type=code&redirect_uri=https://callback_url/auth&client_id=FQ9RGtMkztAgmAApKOqACrBNq&state=7tvPJiv8StrAqo9IQE9xsJaDso4&scope=+profile+email+phone+group+role+resource
+```
 
 ## How to exploit
-1. OAuth token stealing: Changing redirect_uri to attacker.com(Use IDN Homograph or common bypasses).
-2. Change Referral header to attacker.com while requesting OAuth.
-3. Create an account with victim@gmail.com with normal functionality. Create account with victim@gmail.com using OAuth functionality. Now try to login using previous credentials.
-4. OAuth Token Re-use.
-5. Missing or broken state parameter.
-6. Lack of origin check.
-7. Open Redirection on another endpoint > Use it in redirect_uri
-8. If there is an email parameter after signin then try to change the email parameter to victim's one.
-9. Try to remove email from the scope and add victim's email manually.
-10. Only company's email is allowed? > Try to replace hd=company.com to hd=gmail.com
-11. Check if its leaking client_secret parameter.
-12. Go to the browser history and check if the token is there.
+1. OAuth token stealing by changing `redirect_uri` and Use IDN Homograph
+   * Normal parameter
+        ```
+        &redirect_uri=https://example.com
+        ```
+    * IDN Homograph
+        ```
+        &redirect_uri=https://еxamplе.com
+        ```
+    If you notice, im not using the normal `e`
+2. Create an account with victim@gmail.com with normal functionality. Create account with victim@gmail.com using OAuth functionality. Now try to login using previous credentials.
+3. OAuth Token Re-use.
+4. Improper handling of state parameter
+
+    To exploit this, go through the authorization process under your account and pause immediately after authorization. Then send this URL to the logged-in victim
+    * CSRF Attack
+        ```html
+        <a href="https://example.com/authorize?client_id=client1&response_type=code&redirect_uri=http://callback&scope=openid+email+profile">Press Here</a>
+        ```
+5. Lack of origin check.
+6. Open Redirection on `redirect_uri` parameter
+    * Normal parameter
+        ```
+        &redirect_uri=https://example.com
+        ```
+    * Open Redirect
+        ```
+        &redirect_uri=https://evil.com
+        &redirect_uri=https://example.com.evil.com
+        etc.
+        ```
+7. If there is an email parameter after signin then try to change the email parameter to victim's one.
+8.  Try to remove email from the scope and add victim's email manually.
+9.  Check if its leaking `client_secret`
 
 ## References
 * [tuhin1729_](https://twitter.com/tuhin1729_/status/1417843523177484292)