We set up file permissions in a hurry:

• chmod 777 (it just works)
• chmod 666 (for testing)
• No SUID audit (it's just one binary)
• Open temp files (gotta ship)

We hear warnings but keep driving.

DO:

curl -L https://github.com/nickciolpan/permcheck/releases/latest/download/permcheck-linux-amd64 -o permcheck
chmod +x permcheck
sudo mv permcheck /usr/local/bin/

Catches:

• World-writable files
• SUID/SGID binaries
• Insecure temp files
• Overly permissive directories

Real output:

╔══════════════════════════════════════════════════════════════════╗
║                    🔒 SECURITY SCAN INITIATED                   ║
╚══════════════════════════════════════════════════════════════════╝

🌍 WORLD-WRITABLE FILES (2 found):
  ⚠️  /home/user/project/config.txt (0666)
      💡 World-writable means ANY user can modify this file!
      💡 Consider: chmod 644 /home/user/project/config.txt

Setup (30 seconds)

Add to CI:

- name: Security Scan
  run: permcheck scan

30 seconds to install. Catches stupid mistakes before production.

Best Practices

• Executables: 755 (rwxr-xr-x)
• Configuration: 644 (rw-r--r--)
• Sensitive data: 600 (rw-------)
• Directories: 755 (rwxr-xr-x)

Never use:

• 777 (rwxrwxrwx)
• 666 (rw-rw-rw-)
• Any world-writable permissions

GitHub: https://github.com/nickciolpan/permcheck

What's your worst file permission mistake?