GHSA-7m72-mh5r-6j3r: Privilege escalation in project role template binding (PRTB) and -promoted roles
ImpactAn issue was discovered in Rancher versions from 2.5.0 up to and including 2.5.16 and from 2.6.0 up to and including 2.6.9, where an authorization logic flaw allows privilege escalation via project role template binding (PRTB) and `-promoted` roles. This issue is not present in Rancher 2.7 releases.Note: Consult Rancher [documentation](https://ranchermanager.docs.rancher.com/how-to-guides/new-user-guides/authentication-permissions-and-global-configuration/manage-role-based-access-control-rbac/cluster-and-project-roles) for more information about cluster and project roles and [KB 000020097](https://www.suse.com/support/kb/doc/?id=000020097) for information about `-promoted` roles.This privilege escalation is possible for users with access to the `escalate` verb on PRTBs (`projectroletemplatebindings.management.cattle.io`), including users with `*` verbs on PRTBs (see notes below for more information). These users can escalate permissions for any `-promoted` resource (see the table below for a full enumeration) in any cluster where they have a PRTB granting such permissions in at least one project in the cluster.On a default Rancher setup, only the following roles have such permissions:Project OwnerManage Project MembersThese roles have permissions to affect the following resources:| Resource | API Group | Affected Rancher version |
| - | - | - |
| navlinks | ui.cattle.io | 2.6 |
| nodes | "" | 2.6 |
| persistentvolumes | "" | 2.5, 2.6 |
| persistentvolumes | core | 2.5, 2.6 |
| storageclasses | storage.k8s.io | 2.5, 2.6 |
| apiservices | apiregistration.k8s.io | 2.5, 2.6 |
| clusterrepos | catalog.cattle.io | 2.5, 2.6 |
| clusters (`local` only) | management.cattle.io | 2.5, 2.6 |Notes:During the calculation of the CVSS score, `privileges required` was considered  as `high` because, by default, `standard user` and `user-base` users in Rancher do not have  `create`, `patch` and `update` permissions on `roletemplates`.If a role template with access to those objects was already created by another user in the cluster, then this issue can be exploited by users without the mentioned permissions from point 1.WorkaroundsIf updating Rancher to a patched version is not possible, then the following workarounds must be observed to mitigate this issue:Only grant Project Owner and Manage Project Members roles to trusted users.Minimize the creation of custom roles that contain the `escalate`, `*` or write verbs (`create`, `delete`, `patch`, `update`) on `projectroletemplatebindings` resource, and only grant such custom roles to trusted users.Minimize the number of users that have permissions to `create`, `patch` and `update` `roletemplates`.PatchesPatched versions include releases 2.5.17 and 2.6.10 and later versions. This issue is not present in Rancher 2.7 releases.DetectionThe following script was developed to list role template bindings that give written access to the affected resources listed above. It is highly recommended to run the script in your environment and review the list of identified roles and role template bindings for possible signs of exploitation of this issue. The script requires `jq` installed and a `kubeconfig` with access to Rancher local cluster; it can also be executed in Rancher's kubectl shell.For more informationIf you have any questions or comments about this advisory:Reach out to [SUSE Rancher Security team](https://github.com/rancher/rancher/security/policy) for security related inquiries.Open an issue in [Rancher](https://github.com/rancher/rancher/issues/new/choose) repository.Verify our [support matrix](https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/) and [product support lifecycle](https://www.suse.com/lifecycle/)
CVSS v3.1: 7.2