🛡️ Linux System Security Checker

A lightweight and powerful Bash script designed to perform a quick security audit of your Linux system. This tool checks for firewall status, sensitive file permissions, inactive users, running services, and available updates, then generates a detailed security report in both text and HTML formats.

Features

• Firewall Status: Checks if UFW is active and lists current rules.
• Sensitive File Permissions: Verifies permissions for critical files like /etc/passwd, /etc/shadow, and /etc/hosts.
• Inactive User Accounts: Lists users with no login shell (e.g. /bin/false, nologin).
• Users with Login Shells: Lists users who can log in (security audit).
• Service Monitoring: Lists top 10 running services by memory usage.
• System Updates: Checks for available package updates (supports apt, dnf, yum).
• Detailed Report: Automatically generates a comprehensive security report in both text and HTML formats for better visualization.

Directory Structure

linux-system-security-checker/
├── security-checker.sh
├── README.md
├── LICENSE
├── security-report.txt
├── security-report.html
└── example-report.txt

Usage

1. Clone this repository:

   git clone https://github.com/m-ah07/linux-system-security-checker.git
   cd linux-system-security-checker

2. Make the script executable:

   chmod +x security-checker.sh

3. Run the script:

   ./security-checker.sh

4. View the generated report:

   • Text Report:

     cat security-report.txt

   • HTML Report: Open security-report.html in your favorite browser.

Example Report

Here's an example of the output generated by the script:

Security Report - Thu Dec 21 2024
---------------------------------------
Firewall Status:
Status: active

To                         Action      From
--                         ------      ----
22                         ALLOW       Anywhere
---------------------------------------
File Permissions:
/etc/passwd -rw-r--r--
/etc/shadow -rw-------
/etc/hosts -rw-r--r--
---------------------------------------
Inactive Users (cannot login):
daemon
bin
sys
...
---------------------------------------
Users with Login Shells (can login):
root
admin
---------------------------------------
Top 10 Running Services by Memory Usage:
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.1 102400  9280 ?       Ss   12:00   0:03 /sbin/init
mysql      172  0.5  1.5 125000 11000 ?       Ssl  12:00   0:30 /usr/sbin/mysqld
---------------------------------------
System Updates:
System is up-to-date.

HTML Format:

Open security-report.html for a visually styled version of the report with structured sections and improved readability.

Contributing

We welcome contributions to improve this tool! Here's how you can help:

• Report issues: Found a bug? Open an issue and let us know.
• Suggest features: Have an idea for improvement? We'd love to hear it.
• Submit pull requests: Contribute code directly to the repository.

Future Improvements

• Task Scheduling: Add cron job integration for automated periodic checks.
• Vulnerability Scanner: Integrate CVE vulnerability scanning.
• Enhanced HTML Report: Include charts and visual statistics.
• Customizable Rules: Allow users to define custom rules for security checks.

Show Your Support

If you found this project helpful, please consider giving it a ⭐ on GitHub. Your support means the world to us!