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In the world of cybersecurity, discovering exposed access tokens is crucial for penetration testers and ethical hackers. Tools like FFUF (Fuzz Faster U Fool) and GAU (Get All URLs) can help automate this process efficiently.
You Should Know: FFUF and GAU for Access Token Discovery
1. Installing FFUF and GAU
Before using these tools, ensure they are installed on your Linux system:
Install FFUF go install github.com/ffuf/ffuf@latest Install GAU go install github.com/lc/gau@latest
2. Gathering URLs with GAU
GAU fetches known URLs from various sources, including Wayback Machine and Common Crawl.
gau example.com | tee urls.txt
3. Fuzzing for Access Tokens with FFUF
Use FFUF to scan for exposed tokens in the gathered URLs:
ffuf -w urls.txt -u FUZZ -H "Authorization: Bearer FUZZ" -mr "token"
4. Filtering Valid Tokens
Extract potential tokens and verify them:
cat urls.txt | grep -Eo "access_token=[^&]+" | cut -d '=' -f2 > tokens.txt
5. Automating the Process
Combine GAU and FFUF in a script:
!/bin/bash domain=$1 gau $domain | tee urls.txt ffuf -w urls.txt -u FUZZ -H "Authorization: Bearer FUZZ" -mr "token" -o results.json
6. Checking Token Validity
Use `curl` to verify if tokens are active:
while read token; do
curl -H "Authorization: Bearer $token" https://api.example.com/user -s -o /dev/null -w "%{http_code}\n"
done < tokens.txt
What Undercode Say
Finding exposed access tokens is a critical step in penetration testing. Automation with GAU and FFUF speeds up reconnaissance, but always ensure proper authorization before testing.
Additional Useful Commands
- Extracting JWT Tokens from Logs:
grep -E "eyJ[A-Za-z0-9_-].[A-Za-z0-9_-].[A-Za-z0-9_-]" logs.txt
Decoding JWT Tokens:
echo "JWT_TOKEN" | jq -R 'split(".") | .[bash],.[bash] | @base64d | fromjson'Checking API Rate Limits:
curl -I -H "Authorization: Bearer TOKEN" https://api.example.com
Windows Equivalent (PowerShell):
(Invoke-WebRequest -Uri "https://api.example.com" -Headers @{"Authorization"="Bearer TOKEN"}).StatusCode
Expected Output:
A list of potential access tokens and their HTTP validation status.
Relevant Course URLs:
References:
Reported By: Zlatanh Find – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
