A Server Side Request Forgery (SSRF) vulnerability in tools/files/importers/remote.php in concrete5 8.2.0 can lead to attacks on the local network and mapping of the internal network, because of URL functionality on the File Manager page.
An issue was discovered in tools/conversations/view_ajax.php in Concrete5 before 8.3.0. An unauthenticated user can enumerate comments from all blog posts by POSTing requests to /index.php/tools/required/conversations/view_ajax with incremental 'cnvID' integers.
concrete5 8.1.0 has CSRF in Thumbnail Editor in the File Manager, which allows remote attackers to disable the entire installation by merely tricking an admin into viewing a malicious page involving the /tools/required/files/importers/imageeditor?fID=1&imgData= URI. This results in a site-wide denial of service making the site not accessible to any users or any administrators.
concrete5 8.1.0 places incorrect trust in the HTTP Host header during caching, if the administrator did not define a "canonical" URL on installation of concrete5 using the "Advanced Options" settings. Remote attackers can make a GET request with any domain name in the Host header; this is stored and allows for arbitrary domains to be set for certain links displayed to subsequent visitors, potentially an XSS vector.
Multiple cross-site scripting (XSS) vulnerabilities in concrete5 5.7.2.1, 5.7.2, and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) gName parameter in single_pages/dashboard/users/groups/bulkupdate.php or (2) instance_id parameter in tools/dashboard/sitemap_drag_request.php.
Cross-site scripting (XSS) vulnerability in single_pages\download_file.php in concrete5 before 5.6.3 allows remote attackers to inject arbitrary web script or HTML via the HTTP Referer header to index.php/download_file.