GHSA-pjhg-9wr9-rj96

Description

### Impact An open redirect vulnerability in the HTML conversion request filter allows attackers to construct URLs on an XWiki instance that redirect to any URL. To reproduce, open `<xwiki-host>/xwiki/bin/view/Main/?foo=bar&foo_syntax=invalid&RequiresHTMLConversion=foo&xerror=https://www.example.com/` where `<xwiki-host>` is the URL of your XWiki installation. ### Patches This bug has been fixed in XWiki 15.10.13, 16.4.4 and 16.8.0 by validating the domain of the redirect URL against the configured safe domains and the current request's domain. ### Workarounds A web application firewall could be configured to reject requests with the `xerror` parameter as from our analysis this parameter isn't used anymore. For requests with the `RequiresHTMLConversion` parameter set, the referrer URL should be checked if it points to the XWiki installation. Apart from that, we're not aware of any workarounds.