Challenge list

API Requests - Find the Highest-Profit Trade

When the container starts, a stock API begins running on http://localhost:9102 (you do not need to start server.py).…

Linux-02. Privilege Escalation via a Sudo-Allowed Vim

Check which commands a regular user can run via sudo without a password. A well-known GTFOBins technique can let you…

Linux-03. Reading Cron Configuration Files

This system has several cron configurations (/etc/cron.d, /etc/crontab, user crontabs, and more). Inspect each…

Linux-Cron Privesc. Hijacking a Writable Root Script

Check the permissions of a cron script that root executes periodically. If a regular user can write to it, think about…

55 ptsOpen challenge

Linux-Systemd. Checking a Service Unit's Environment Variable

A systemd unit file can set environment variables in its [Service] section. Inspect the registered service definition…

Linux-Symlink Maze. Navigating a Branching Path

Several directories are connected in a tangled web of symbolic links. Without being misled by decoy hint files, follow…

Linux-Script Debug. Fixing a Broken Bash Script

This script has several intentional bugs (typos, syntax mistakes) and fails to run to completion. Use bash's debugging…

55 ptsOpen challenge

Linux-Network Basics. Connecting to a Listening Port

A background service on this system is listening on a specific port. Identify the port with ss/netstat and connect to…

Linux-Backup Finder. Spotting the Real Temp File

The project directory contains several decoy backup/temp files ending in .bak, .tmp, or ~. The real flag is hidden…

40 ptsOpen challenge

Linux-Pipeline. Narrowing Down Logs with grep and awk

The access log contains many entries. One IP address generated a burst of 404s, and stitching together the paths of…

Linux-Package Info. Inspecting Installed Package Details

A custom-built deb package is installed on this system. Use dpkg or apt to inspect the package's details and find…

Linux-Process Hunting. Tracking Down a Running Process

Among several background processes, one has the flag embedded in its command-line arguments. List them with ps and…

Linux-User Investigation. Filtering the Target User with awk

Several users are registered on this system. Parse /etc/passwd with awk to find the one matching a specific condition,…

Linux-Log Rotation. Searching Compressed Historical Logs

Some older log files have been gzip-compressed by log rotation. Use a command that searches inside compressed files…

Linux-Log Explorer. Digging the Flag Out of Multiple Logs

Multiple application and system log files are provided. The flag is embedded in a single DEBUG-level line — narrow it…

Linux-Environment Secrets. Finding the Variable Named FLAG

Several environment variables, including some dummy credentials, are set on this system. List them with env and find…

Python Practice - Bulk Base64 Stream Decoding

Every line of data.txt (about 150 lines, created at every start) is Base64. Decode line by line; when the result…

Python Practice - Conditional CSV Sales Filtering

data.txt, created at every start, is a sales CSV (transaction_id,date,product_id,amount,status,ref,notes). Several…

Python Practice - Compound JSON User Query

Examine the JSON data.txt ({"users": [...]}) created at every start. Each user has id, name, email, role, active and…

Python Practice - Target-IP Access Log Tracing

data.txt (about 1,300 lines, created at every start) is a web server access log. Extract only the requests from…

Python Automation - Bulk Base64 Decoding

Every line of data.txt (about 150 lines, created at every start) is Base64. Decode line by line; when the result…

40 ptsOpen challenge

Python Automation - CSV Sales Filtering

data.txt, created at every start, is a sales CSV (transaction_id,date,product_id,amount,status,ref,notes). Several…

Python Automation - JSON User Query

Examine the JSON data.txt ({"users": [...]}) created at every start. Each user has id, name, email, role, active and…