kiwitcms vulnerable to stored cross-site scripting via unrestricted file upload
ImpactKiwi TCMS allows users to upload attachments to test plans, test cases, etc. Earlier versions of Kiwi TCMS had introduced upload validators in order to prevent potentially dangerous files from being uploaded and Content-Security-Policy definition to prevent cross-site-scripting attacks.The upload validation checks were not 100% robust which left the possibility to circumvent them and upload a potentially dangerous file which allows execution of arbitrary JavaScript in the browser. Additionally we've discovered that Nginx's `proxy_pass` directive will strip some headers negating protections built into Kiwi TCMS when served behind a reverse proxy.PatchesImproved file upload validation codeUpdated Nginx reverse proxy configuration for ***.tenant.kiwitcms.org**WorkaroundsIf serving Kiwi TCMS behind a reverse proxy make sure that additional header values are still passed to the client browser. If they aren't redefine them inside the proxy configuration. See [etc/nginx.conf#L66-L68](https://github.com/kiwitcms/Kiwi/blob/master/etc/nginx.conf#L66-L68) and [etc/nginx.conf#L87](https://github.com/kiwitcms/Kiwi/blob/master/etc/nginx.conf#L87)ReferencesDisclosed by [M Nadeem Qazi](https://huntr.dev/bounties/6aea9a26-e29a-467b-aa5a-f767f0c2ec96/).