Detecting and exploiting path-relative stylesheet import (PRSSI) vulnerabilities

Published

2021-02-10 14:29

Collected

2026-07-27 07:19

---
id: 5550
title: "Detecting and exploiting path-relative stylesheet import (PRSSI) vulnerabilities"
source_domain: portswigger.net
source_url: "https://portswigger.net/research/detecting-and-exploiting-path-relative-stylesheet-import-prssi-vulnerabilities"
published_at: "2021-02-10T14:29:00Z"
tags: ["phpbb", "css-injection", "browser-quirks", "prssi", "relative-path-overwrite"]
phying_url: "https://phying.com/item/5550"
lang: en
---

# Detecting and exploiting path-relative stylesheet import (PRSSI) vulnerabilities

## Summary

James Kettle walks through path-relative stylesheet import (PRSSI) vulnerabilities, the Relative Path Overwrite technique that tricks browsers into loading HTML as CSS, using a real phpBB3 example.

## Intelligence Metadata

- **Sources:** portswigger.net
- **Published:** 2021-02-10T14:29:00Z
- **Original:** https://portswigger.net/research/detecting-and-exploiting-path-relative-stylesheet-import-prssi-vulnerabilities
- **Phying News:** https://phying.com/item/5550