What I Learned from Reading 217* Subdomain Takeover Bug Reports

In the world of cybersecurity, few vulnerabilities capture the attention of both seasoned professionals and curious newcomers like the subdomain takeover. A potent mix of misconfiguration, negligence, and oversight often leads to this critical vulnerability, allowing attackers to hijack subdomains and potentially exploit them for malicious purposes. To truly understand the mechanics, risks, and prevention strategies of subdomain takeovers, I immersed myself in 217* bug reports detailing real-world cases of this vulnerability.

In this blog, I’ll share what I learned from these reports, offering insights into the patterns, common mistakes, and best practices that can help secure your digital assets against subdomain takeovers.

1. Understanding Subdomain Takeovers

Before delving into the specifics of the bug reports, it’s crucial to grasp what subdomain takeovers are and why they pose such a significant threat.

What is a Subdomain Takeover?

A subdomain takeover occurs when an attacker gains control over a subdomain that still exists in the DNS (Domain Name System) but is no longer properly associated with a service. This typically happens when a company decommissions a resource but forgets to…