Affected: Red Hat, Inc. keycloak

It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web resource locations. An attacker could use this flaw against an authenticated user to attain reflected XSS via a malicious server.

Affected: Maven: io.vertx:vertx-web

# Description

- In the `StaticHandlerImpl#sendDirectoryListing(...)` method under the `text/html` branch, file and directory names are directly embedded into the `href`, `title`, and link text without proper HTML escaping. - As a result, in environments where an attacker can control file names, injecting HTML/JavaScript is possible. Simply accessing the directory listing page will trigger an XSS. - Affected Code: - File: `vertx-web/src/main/java/io/vertx/ext/web/handler/impl/StaticHandlerImpl.java` - Lines: - 709–713: `normalizedDir` is constructed without escaping - 714–731: `<li><a ...>` elements insert file names directly into attributes and body without escaping - 744: parent directory name construction - 746–751: `{directory}`, `{parent}`, and `{files}` are inserted into the HTML template without escaping

# Reproduction Steps

1. Prerequisites: - Directory listing is enabled using `StaticHandler` (e.g., `StaticHandler.create("public").setDirectoryListing(true)`) - The attacker has the ability to create arbitrary file names under a public directory (e.g., via upload functionality or a shared directory)

2. Create a malicious file name (example for Unix-based OS): - Create an empty file in `public/` with one of the following names: - `<img src=x onerror=alert('XSS')>.txt` - Or attribute injection: `evil" onmouseover="alert('XSS')".txt` - Example: ```bash mkdir -p public printf…