# Cross-site Scripting in gamma.js of GammaGalery

## Author: TuanNQ (https://github.com/tuannq2299)
## Vendor: https://github.com/codrops/GammaGallery

## Description:
Injecting any parameter in the URL query can result in XSS vulnerabilities.

## Demo page (https://tympanus.net/Development/GammaGallery/)
Add any parameter in URL query, the payload is then triggered.

https://tympanus.net/Development/GammaGallery/?abc=prompt(origin)

## Root cause
The root cause of this vulnerability is in the logic of the code from L62-L65 `/js/gamma.js`. In the above step, all parameter in URL query was extracted, then their value will be passed to the `eval()` (L65) which leads to the `prompt()` in the demo.