Concrete CMS version 9 before 9.2.8 and previous versions prior to 8.5.16 is vulnerable to Stored XSS on the calendar color settings screen since Information input by the user is output without escaping. A rogue administrator could inject malicious javascript into the Calendar Color Settings screen which might be executed when users visit the affected page. The Concrete CMS security team gave this vulnerability a CVSS v3.1 score of 2.0 with a vector of AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N&version=3.1 https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator
Thank you Rikuto Tauchi for reporting
Concrete CMS before 8.5.14 and 9 before 9.2.3 allows Cross Site Request Forgery (CSRF) via ccm/calendar/dialogs/event/delete/submit. An attacker can force an admin to delete events on the site because the event ID is numeric and sequential.
Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because directories can be created with insecure permissions. File creation functions (such as the Mkdir() function) gives universal access (0777) to created folders by default. Excessive permissions can be granted when creating a directory with permissions greater than 0755 or when the permissions argument is not specified.
Concrete CMS (previously concrete5) versions 8.5.12 and below, and 9.0 through 9.1.3 does not have Secure and HTTP only attributes set for ccmPoll cookies.
Concrete CMS (previously concrete5) versions 8.5.12 and below, and versions 9.0 through 9.1.3 is vulnerable to Reflected XSS on the Reply form because msgID was not sanitized.