Grav CMS 2.0.14 through 2.0.24 Privilege Escalation via Blueprint Guard Bypass

Grav CMS 2.0.14 through 2.0.24 contains a privilege escalation vulnerability in the group and account blueprints. The access map is gated by a security@: admin.super guard that is resolved by the field's exact path, so a submitted flat dot-notation key such as access.admin.super (instead of the nested access[admin][super]) matches no blueprint rule, survives BlueprintSchema::filterArray() and flattening, and is written by FlexObject::update() via setNestedProperty(), which splits on . and reconstructs the nested value. An authenticated backend operator using the flex accounts backend who holds admin.users but not admin.super can therefore grant admin.super to their own account or to a group they belong to and escalate to full super-admin, gaining control over configuration, plugin and theme installation, the file manager, and all accounts. Fixed in 2.0.25, which drops any dotted key whose ancestor path is disabled or marked validate.ignore.