Pydio Cells 4.1.2 Cross Site Scripting
Posted on 30 May 2023
Pydio Cells versions 4.1.2 and below implement the download of files using presigned URLs which are generated using the Amazon AWS SDK for JavaScript. The secrets used to sign these URLs are hardcoded and exposed through the JavaScript files of the web application. Therefore, it is possible to generate valid signatures for arbitrary download URLs. By uploading an HTML file and modifying the download URL to serve the file inline instead of as an attachment, any included JavaScript code is executed when the URL is opened in a browser, leading to a cross site scripting vulnerability.
