GHSA-94qw-r73x-j7hg Users with ROLE_COURSE_ADMIN can create new users in Opencast

• Maven org.opencastproject:opencast-kernel: < 7.6 → fixed in 7.6 • Maven org.opencastproject:opencast-kernel: >= 8.0, < 8.1 → fixed in 8.1

Impact Users with the role `ROLE_COURSE_ADMIN` can use the user-utils endpoint to create new users not including the role `ROLE_ADMIN`. For example: ```bash Use the admin to create a new user with ROLE_COURSE_ADMIN using the admin user. We expect this to work. % curl -i -u admin:opencast 'https://example.opencast.org/user-utils/xy.json' -X PUT \ --data 'password=f&roles=%5B%22ROLE_COURSE_ADMIN%22%5D' HTTP/2 201 Use the new user to create more new users. We don't expüect a user with just role ROLE_COURSE_ADMIN to succeed. But it does work % curl -i -u xy:f 'https://example.opencast.org/user-utils/ab.json' -X PUT \ --data 'password=f&roles=%5B%22ROLE_COURSE_ADMIN%22%5D' HTTP/2 201 ``` `ROLE_COURSE_ADMIN` is a non-standard role in Opencast which is referenced neither in the documentation nor in any code (except for tests) but only in the security configuration. From the name – implying an admin for a specific course – users would never expect that this role allows user creation. Patches This issue is fixed in 7.6 and 8.1 which both ship a new default security configuration. Workarounds You can fix this issue by removing all instances of `ROLE_COURSE_ADMIN` in your organization's security configuration (`etc/security/mh_default_org.xml` by default). For more information If you have any questions or comments about this advisory: • Open an issue in opencast/opencast • For security-relevant information, email us at [email protected]