API_Recon

Passive Recon

• find public API documentations by searching the internet for company_name API or company_name developer docs

• company_name inurl:swagger, This documentation often includes all API endpoints even the private, their input parameters, and sample responses

• Google Dorking

  • inurl:"/wp-json/wp/v2/users"

  • intitle:"index.of" intext:"api.txt"

  • inurl:"/api/v1" intext:"index of /"

• Shodan

  • hostname:"targetname.com"

  • content-type: application/json

  • content-type: application/xml

  • wp-json

• The Wayback Machine

  • Finding and comparing historical snapshots of API documentation can simplify testing for Improper Assets Management.

  • Test for older Versions ex-> /api/v2/user_emails -> `/api/v1/user_emails

Active Recon

• search for other API endpoints by using recon techniques from Web_Recon

• Try Fuzzing techniques for discovering API endpoints and resources, the best for APIs is Kite Runner

  • kiterunner:

kr scan HTTP://127.0.0.1 -w ~/api/wordlists/data/kiterunner/routes-large.kite
kr scan https://domain.com/api/ -w routes-large.kite -x 20
kr scan https://domain.com/api/ -A=apiroutes-220828 -x 20
kr brute https://domain.com/api/ -A=raft-large-words -x 20 -d=0
kr brute https://domain.com/api/ -w /tmp/lang-english.txt -x 20 -d=0

• nmap

  • nmap -sC -sV [target]

  • nmap -p- [target] all ports

  • nmap -sV --script=http-enum [target] -p 80,443,8000,8080

• amass: amass enum -active/passive -d [target] | grep api

• Map the the App while intercepting requests

• try to generate error messages in hopes that the API leaks information about itself

• understand each API endpoint’s functionality, parameters, and query structure

• Identify all the possible user data input locations

• Look out for any authentication mechanisms, including these:

  • Do access tokens expire when updating or resetting passwords?

  • What access tokens are needed?

  • Which endpoints require tokens and which do not?

  • How are access tokens generated?

  • Can users use the API to generate a valid token without logging in?