CVE-2021-25320 Rancher: Cloud credentials can be used through proxy API by users without access

What is CVE-2021-25320?

CVE-2021-25320 is a critical missing authorization vulnerability in Rancher, published on 15 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A Improper Access Control vulnerability in Rancher, allows users in the cluster to make request to cloud providers by creating requests with the cloud-credential ID. Rancher in this case would attach the requested credentials without further checks This issue affects: Rancher versions prior to 2.5.9; Rancher versions prior to 2.4.16.

Weakness: CWE-284

Which versions are affected by CVE-2021-25320?

5 open source packages ship an affected version, including github.com/rancher/rancher. It affects 1 product.

Products include Rancher Rancher.

How do I fix CVE-2021-25320?

Upgrade github.com/rancher/rancher to a fixed version for your release line: 2.4.16 or 2.5.9.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2021-25320 being exploited?

There is no known exploitation of CVE-2021-25320 in the wild and no public exploit code.

Other vulnerabilities in Rancher

• CVE-2021-36775 Deleting PRTBs associated to a group doesn't cause deletion of corresponding RoleBindings High 8.8
• CVE-2021-36776 Steve API proxy impersonation High 8.8
• CVE-2021-25318 rancher: API group not properly specified when creating Kubernetes RBAC resources High 8.8
• CVE-2021-31999 Rancher: Privilege escalation vulnerability via malicious Connection header High 8.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-gqf8-rvrh-g7w6, GO-2026-4589.