Challenge list
CryptographyLevel 2★★☆☆☆Breaking Small RSA Keys
Factor a tiny RSA modulus, recover the private exponent, and decrypt a list of ciphertext values. Public key and…
CryptographyLevel 2★★☆☆☆Cryptanalysis - Breaking the Affine Cipher
ciphertext.txt is an English report encrypted with the affine cipher E(x) = (a*x + b) mod 26. Letter case is preserved…
LinuxLevel 3★★★☆☆Linux-Capabilities. Privilege Escalation Beyond SUID
A specific binary on this system has Linux capabilities assigned to it. Investigate a privilege escalation technique…
LinuxLevel 3★★★☆☆Linux-SUID Exploit. Escalating Privileges via the find Binary
A copy of the find command with the SUID bit set exists on this system. Use a well-known GTFOBins technique to obtain…
LinuxLevel 3★★★☆☆Linux-Proc Memory. Peeking at a Process's Environment
A daemon process runs continuously in the background, with the flag set as one of its environment variables.…
LinuxLevel 3★★★☆☆Linux-Strace. Tracing System Calls to Expose a File
A binary that leaves nothing in standard output or on disk is provided. It reads a key from a hidden file,…
LinuxLevel 3★★★☆☆Linux-Race Condition. Exploiting a TOCTOU Gap for Root Files
A cleanup script that root runs periodically has a gap (TOCTOU) between checking and acting on a file. Try exploiting…
Web SecurityLevel 3★★★☆☆Web-21. Blind Injection in Secure User Search
This user search app only reports whether a username exists, without showing direct query results. Investigate whether…
Web SecurityLevel 3★★★☆☆Web-22. CSP Bypass on the Secure Comment Board
This comment board is protected by a Content Security Policy restricting script execution to the site itself and a…
Web SecurityLevel 3★★★☆☆Web-23. Type Juggling in the Secure Authentication System
This login portal supports form login, a JSON API login, and a verification-code check. The admin account's real…
Web SecurityLevel 3★★★☆☆Web-24. Exploiting a Race Condition in Secure Bank
Secure Bank lets users spend a coin balance on shop prizes. If the balance check and the deduction happen as two…
Web SecurityLevel 3★★★☆☆Web-25. SSTI in the Greeting Card Generator
This greeting card generator is built with Flask/Jinja2 and renders the user's message directly through the template…
Network SecurityLevel 3★★★☆☆Network Analysis - 802.1Q VLAN Separated Traffic
capture.pcap was captured from a mirrored switch trunk port, so frames from several VLANs are mixed together with…
Network SecurityLevel 3★★★☆☆Network Analysis - SNMP Information Leak
A device speaking SNMPv2c with a weak community string (public) was captured returning a GetResponse. Download the…
Network SecurityLevel 3★★★☆☆Network Analysis - SSL Strip Clear-text Credentials
An SSL Strip attack downgraded HTTPS to HTTP, so the victim's credentials traveled in clear text and were captured.…
Network SecurityLevel 3★★★☆☆Network Analysis - Unmasking WebSocket Frames
capture.pcap records WebSocket traffic between a browser and a chat server. Every client-to-server frame is masked…
Network SecurityLevel 3★★★☆☆Network Analysis - Custom Protocol Decoding
Traffic from a system using a small custom binary protocol was captured. Download the packet capture (traffic.pcap),…
CryptographyLevel 3★★★☆☆Cryptanalysis - RSA Common Modulus Attack
Two systems reused the same RSA modulus n and only changed the public exponent. The ciphertexts c1 and c2 of the same…
CryptographyLevel 3★★★☆☆Cryptanalysis - Diffie-Hellman with a Small Prime
An old IoT device performed Diffie-Hellman key exchange with a prime p of only 36 bits. handshake.txt contains p, g, A…
LinuxLevel 4★★★★☆Linux-Kernel Module. Gaining Root via a Vulnerable Driver
This challenge analyzes a vulnerable character-device driver as a safe user-space simulation. No real kernel module is…
LinuxLevel 4★★★★☆Linux-Buffer Overflow. Exploiting a gets() Vulnerability
A vulnerable SUID C binary with protections disabled is provided. Exploit its buffer overflow to redirect control flow…
Web SecurityLevel 4★★★★☆Web-26. Prototype Pollution in User Profile Manager
In this Node.js/Express app, a logged-in user can update their own profile. Check whether the recursive merge function…
Web SecurityLevel 4★★★★☆Web-27. GraphQL Introspection Leak
This GraphQL API exposes a schema of User objects with introspection enabled. Investigate whether undocumented queries…
Web SecurityLevel 4★★★★☆Web-28. Hijacking an OAuth Authorization Code
This OAuth 2.0 authorization provider offers a login flow, but its redirect_uri validation may be weak. Investigate…