Impact

This issue only affects Rancher instances with Azure AD integration enabled, regardless of the automatically refreshing settings which are enabled by default. The users that obtained a token (or kubeconfig) to access Rancher through the following sessions are affected by this issue:

1. Users using the Rancher UI.
2. Users using kubectl based on a kubeconfig downloaded through the Rancher UI.
3. Tokens created via the Rancher UI Create API Key feature.

A bug has been identified in which permission changes in Azure AD are not reflected to users while they are logged in the Rancher UI. This would cause the users to retain their previous permissions in Rancher, even if they change groups on Azure AD, for example, to a lower privileged group, or are removed from a group, thus retaining their access to Rancher instead of losing it.

Note that the permission caching is persisted even when the Rancher Manager pod is restarted. The only way for a user to get the new permissions is to logout and login again.

Patches

Patched versions include releases 2.6.13, 2.7.4 and later versions.

Workarounds

There is no direct mitigation besides updating Rancher to a patched version.

Credits

We would like to recognize and thank @yvespp for the responsible disclosure of this security issue.

For more information

If you have any questions or comments about this advisory:

• Reach out to the SUSE Rancher Security team for security related inquiries.
• Open an issue in the Rancher repository.
• Verify with our support matrix and product support lifecycle.