$ whoami
Kobie Calingasan
I build full-stack apps and IoT systems. Now I'm learning how to break them.
IT student and freelance developer in the Philippines. Building real things is my strength, and security is what I'm working toward, one lab and CTF at a time.
4th
place, Multi-Sectoral CTF at Philippine Army HQ, Fort Bonifacio
18
projects built across software and hardware
4
security writeups from labs and practice
Featured projects
ls --all
2026
LakBites
A mobile-first app that shows which Filipino street-food vendors are out near you right now, and gives vendors tools to manage their presence.
- React
- TypeScript
- Express
- Supabase
- Capacitor
STATUS: BUILDING
What I build
- Full-stack web and mobile apps
- ESP32 and Arduino IoT systems
- 3D interfaces with three.js
- Multiplayer games on Roblox
STATUS: LEARNING
What I'm learning
- Web vulnerabilities and how to fix them
- Linux privilege escalation labs
- Network enumeration
- CTF competitions
I'm early in my security journey and don't have bug bounty findings yet. My writeups come from labs and practice.
Security notes
ls --allSQL Injection: Login Bypass on VulnApp
MediumExploiting a classic SQL injection vulnerability in a login form to bypass authentication and gain admin access on a deliberately vulnerable web application.
Linux Privilege Escalation via Misconfigured SUID Binary
HardEscalating from a low-privilege shell to root by exploiting a custom SUID binary that invokes system commands without absolute paths, enabling PATH hijacking.
Network Enumeration and Service Discovery
EasyPerforming comprehensive network reconnaissance against a target machine to identify open ports, running services, and potential attack vectors through systematic enumeration.