cve/2024/CVE-2024-21496.md

### [CVE-2024-21496](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-21496)
![](https://img.shields.io/static/v1?label=Product&message=github.com%2Fgreenpau%2Fcaddy-security&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=0%3C%20*%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Cross-site%20Scripting%20(XSS)&color=brighgreen)

### Description

All versions of the package github.com/greenpau/caddy-security are vulnerable to Cross-site Scripting (XSS) via the Referer header, due to improper input sanitization. Although the Referer header is sanitized by escaping some characters that can allow XSS (e.g., [&], [<], [>], ["], [']), it does not account for the attack based on the JavaScript URL scheme (e.g., javascript:alert(document.domain)// payload). Exploiting this vulnerability may not be trivial, but it could lead to the execution of malicious scripts in the context of the target user’s browser, compromising user sessions.

### POC

#### Reference
- https://blog.trailofbits.com/2023/09/18/security-flaws-in-an-sso-plugin-for-caddy/
- https://security.snyk.io/vuln/SNYK-GOLANG-GITHUBCOMGREENPAUCADDYSECURITY-6249860

#### Github
- https://github.com/fkie-cad/nvd-json-data-feeds