CVE-2021-36775: Deleting PRTBs associated to a group doesn't cause deletion of corresponding RoleBindings
Impact This vulnerability only affects customers using group based authentication in Rancher versions up to and including 2.4.17, 2.5.11 and 2.6.2.
When removing a Project Role associated to a group from a project, the bindings that grant access to cluster scoped resources for those subjects do not get deleted. This happens due to an incomplete authorization logic check. A user who is a member of an affected group with authenticated access to Rancher could use this to access resources they should no longer have access to. The exposure level will depend on the original permission level granted to the affected project role.
Patches Patched versions include releases 2.4.18, 2.5.12, 2.6.3 and later versions.
Workarounds Limit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions.
References Cluster and project roles documentation for Rancher 2.6, 2.5 and 2.4.
For more information If you have any questions or comments about this advisory: Reach out to SUSE Rancher Security team for security related inquiries. Open an issue in Rancher repository. Verify our support matrix and product support lifecycle.
Other sources
a Improper Access Control vulnerability in SUSE Rancher allows users to keep privileges that should have been revoked. This issue affects: SUSE Rancher Rancher versions prior to 2.4.18; Rancher versions prior to 2.5.12; Rancher versions prior to 2.6.3.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2021-36775?
CVE-2021-36775 is considered a medium severity vulnerability affecting Rancher versions that utilize group-based authentication.
How do I fix CVE-2021-36775?
To address CVE-2021-36775, upgrade to Rancher version 2.4.18, 2.5.12, or 2.6.3.
Which versions are affected by CVE-2021-36775?
CVE-2021-36775 affects Rancher versions 2.4.17 and earlier, 2.5.11 and earlier, and 2.6.2 and earlier.
What specific impact does CVE-2021-36775 have?
The vulnerability can lead to insufficient access control for cluster scoped resources when project roles are removed from groups.
Who is primarily affected by CVE-2021-36775?
Users of Rancher implementing group-based authentication configurations are primarily impacted by CVE-2021-36775.