2 AM. The screen burned my retinas. Coffee was a memory. The tax-portal.io bug bounty program was a bust. Nothing. Just another dead end in a long line of dead ends. I was ready to quit. Close the laptop. Sleep. One last look at the proxy logs. A flicker in the traffic history. A standard GET request to fetch a user's documents. My own, from my test account. The URL was clean, but the parameter caught my eye. user_id=1054. GET user_id=1054 An Insecure Direct Object Reference. An IDOR. The simplest, most devastating bug in the book. It couldn't be. Not on a financial platform. Muscle memory took over. I sent the request to the repeater tool. The original user_id=1054 was there. My finger hovered over the '4'. Click. Backspace. '5'. user_id=1054 user_id=1055. user_id=1055 Parameter tampering. I forwarded the request. I expected a 403 Forbidden. An error message. A wall. 403 Forbidden The server didn't say no. http GET /api/v1/tax-documents/view?id=1055 HTTP/1.1
Host: secure.tax-portal.io
Cookie: session=eyJh... (My Session)

// RESPONSE (200 OK)
{
  "status": "success",
  "data": {
    "full_name": "Sarah Jenkins",
    "ssn": "***-**-8921",
    "adjusted_gross_income": 85000,
    "refund_status": "PENDING"
  }
} GET /api/v1/tax-documents/view?id=1055 HTTP/1.1
Host: secure.tax-portal.io
Cookie: session=eyJh... (My Session)

// RESPONSE (200 OK)
{
  "status": "success",
  "data": {
    "full_name": "Sarah Jenkins",
    "ssn": "***-**-8921",
    "adjusted_gross_income": 85000,
    "refund_status": "PENDING"
  }
} My blood went cold. Sarah Jenkins. A real person. Her PII, sitting right there on my screen. Her Social Security Number. Her income. All of it. Returned with a cheerful 200 OK. 200 OK This wasn't a bug. It was a hemorrhage. My hands flew. A few lines of Python. A simple loop. for user_id in range(1, 4000000):. I ran the script. for user_id in range(1, 4000000): My terminal flooded with 200 OK. Thousands of them per second. The entire user database. Four million people. Their financial lives, their identities, all exposed to the public internet by a single, broken line of code. 200 OK I killed the script. The silence in the room was deafening. I had it all. I could download everything. I could burn the company to the ground with a single anonymous post. The power was absolute. Intoxicating. I stared at the screen. At Sarah Jenkins' life, reduced to a JSON object. I opened a new text file. My fingers found the keyboard. Title: Critical IDOR Vulnerability in tax-portal.io Leading to Full PII Exposure. Title: tax-portal.io The bounty didn't matter. This was about responsible disclosure. This was about fixing the hole before someone else found it. Someone who wouldn't be so kind.

This story contains AI-generated text. The author has used AI either for research, to generate outlines, or write the text itself. 

The Silicon Trojan

The Zero-Day Deduction

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