Case Study: How Poor Patching and Open Ports Led to the Equifax Breach

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In 2017, one of the most catastrophic breaches in U.S. history occurred — nearly 148 million people had their personal data stolen from Equifax. The cause? A combination of overlooked security basics: an unpatched vulnerability and an exposed web application.
Here’s what happened:
* The Vulnerability: Apache Struts, a web application framework used by Equifax, had a known critical flaw (CVE-2017-5638). A patch was released in March 2017.
* The Exposure: Equifax failed to apply the patch in time. One of their servers with the vulnerable Struts component was accessible via a public-facing web port.
* The Result: Attackers used a remote code execution (RCE) exploit to gain entry, escalate privileges, move laterally across systems, and exfiltrate sensitive data — names, Social Security numbers, birth dates, and more.
What made this worse:
The breach wasn’t discovered for over 2 months.
SSL certificates had expired, impairing internal detection tools.
The database wasn’t encrypted, exposing sensitive records in plaintext.
Lessons for Hackers and Defenders:
1. Open ports aren’t just numbers — they’re doors.
2. Unpatched systems are ticking time bombs.
3. Visibility without monitoring is like locking your front door… and leaving the key under the mat.
The Equifax breach wasn’t a zero-day mystery. It was the result of neglected hygiene — a reminder that security isn’t just about firewalls and passwords. It’s about discipline.
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