Creating a write-up for index.of.password typically refers to one of two things: a technical Google Dorking

Edit your server block configuration.

The "Index of password" vulnerability is a stark reminder that simple configuration errors can have devastating consequences. As search engine crawlers become more efficient, the window between a configuration error and a data breach continues to shrink. Robust server hardening and a "secure by default" mindset are essential to protecting sensitive digital assets from public exposure. Re: Index Of Password Txt Facebook - Google Groups

The index.of.password vulnerability is not a zero-day exploit. It does not require breaking complex cryptography. It is a failure of basic configuration—an oversight so simple that it is often laughed off by junior admins, yet so devastating that it has led to some of the largest data breaches in history.