Subdomain Takeover in Interactsh server
A domain configured with interactsh server was vulnerable to subdomain takeover for specfic subdomain, i.e `app`, Interactsh server before `< 1.0.0` used to create cname entries for `app` pointing to `projectdiscovery.github.io` as default which intended to used for hosting interactsh [web client](https://github.com/projectdiscovery/interactsh-web) using GitHub pages. It turns out to be a security issue with a self-hosted interactsh server in which the user may not have configured a web client but still have a cname entry pointing to GitHub pages, making them vulnerable to subdomain takeover.This issue was initially reported to us as a subdomain takeover for one of our domains that runs interactsh server by **Melih** at `security@projectdiscovery.io`, and after conducting an internal investigation, we determined that it was an issue with the default config of interactsh server affecting all the server running self-hosted instance of interactsh, as a result - cname entry has been removed in the latest release.ImpactThis allows one to host / run arbitrary client side code (XSS) in a user's browser when browsing the vulnerable subdomain, for more details on the impact, please read this [detailed blogpost](https://labs.detectify.com/2014/10/21/hostile-subdomain-takeover-using-herokugithubdesk-more/) from Detectify.PatchesUpdate to [Interactsh server v1.0.0 ](https://github.com/projectdiscovery/interactsh/releases/tag/v1.0.0)with `go install -v github.com/projectdiscovery/interactsh/cmd/interactsh-server@latest`Referenceshttps://github.com/projectdiscovery/interactsh/issues/136For more informationIf you have any questions or comments about this advisory:Email us at [security@projectdiscovery.io](mailto:security@projectdiscovery.io)