CTF Challenges
48 challenges
Crystal Ball
This system generates random numbers for its encryption keys. But how random is random, really? Watch the output long...
Second Life
SecureNotes is an enterprise note-keeping application. User sessions are managed through cookies. Something about how...
Photo Finish
HackShop is an exclusive merch store with one item you really want: the flag. It costs $100, but your coupon is only...
Fence Post
A secure vault application for authorized personnel. The developer wrote a custom input function — surely that's more...
Black Box
A mysterious scoring interface accepts candidate strings and returns a confidence value. Something about the way it...
Health Check
A network diagnostic tool lets you check if hosts are reachable. The developer added some input filtering, but is it...
Greeting Card
A greeting card generator lets you create personalized messages. But what if the application takes your input a little...
Trust Issues
A secure authentication portal protects its admin panel with token-based access control. Log in as a guest and find a...
Talk Back
A debug echo service echoes back whatever you send. But it's echoing more than it should... Your mission: Make the...