Published: February 2025
In one of my recent cybersecurity practice tasks, I was given a scenario: maintain a list of IP addresses that are allowed to access a secure system. Occasionally, some of those IPs must be removed from the list for security reasons — maybe due to expired access, policy changes, or suspicious activity. This gave me the perfect chance to build a practical Python script that mimics real-world firewall management.
Manually editing access lists is risky. Mistakes happen, and as the list grows, it becomes harder to manage. I needed a way to:
I used the `open()` function to read files safely and Python list methods to filter the IPs. Here’s a simplified version of my approach:
import_file = "allow_list.txt"
remove_list = ["192.168.0.101", "192.168.0.105"]
with open(import_file, "r") as file:
ip_addresses = file.read().splitlines()
for ip in remove_list:
if ip in ip_addresses:
ip_addresses.remove(ip)
with open(import_file, "w") as file:
file.write("\n".join(ip_addresses))
This script ensures that only authorized IPs remain on the allowlist — automatically and consistently.
The best part of this task was realizing how much **basic scripting** can help reduce **human error** in cybersecurity. I also practiced working with files, loops, and list operations — foundational skills for automation.
In real-world cybersecurity, **automation** and **principle of least privilege** go hand-in-hand. This kind of script would be useful in a system where dynamic access is granted and revoked regularly — especially in cloud or enterprise environments.
Published: August 2024
While studying real-world cybersecurity case studies, I came across an incident involving a major data leak caused by simple human error and poor access management. It made me reflect on one of the most overlooked — yet powerful — cybersecurity principles: least privilege.
A sales manager shared an internal folder containing confidential files with their team during a product strategy meeting. After the meeting, they forgot to revoke access to that folder. Later, a sales rep accidentally shared a link to the entire folder — thinking they were sharing only the promotional materials — with a business partner.
That partner, unaware of the sensitivity, posted the folder publicly on social media. The damage was done: internal strategy, unreleased product details, and customer analytics were all exposed.
This incident could have been avoided if the organization had enforced the principle of least privilege. This principle means users should only have the **minimum access** needed to do their jobs — and no more.
According to NIST SP 800-53, control AC-6 enforces least privilege by recommending:
Had the team implemented automatic expiration or limited folder access to only necessary documents, the leak likely wouldn't have occurred.
Studying this case reminded me why I care about cybersecurity. It's not just about fancy tools or firewalls — it's about thinking critically and planning access wisely. This principle is simple, powerful, and essential for anyone managing data.
If you're working with shared data, consider using access expiration, folder-specific permissions, and activity logs — even in smaller teams or academic projects.