GHSA-pvxj-25m6-7vqr: Rancher Privilege escalation vulnerability via malicious "Connection" header

1. GitHub Advisory Database
2. GitHub Reviewed
3. CVE-2021-31999

Rancher Privilege escalation vulnerability via malicious “Connection” header

High severity GitHub Reviewed Published Jul 15, 2021 in rancher/rancher • Updated Apr 24, 2024

Package

gomod github.com/rancher/rancher (Go)

Affected versions

>= 2.0.0, < 2.4.16

>= 2.5.0, < 2.5.9

Patched versions

2.4.16

2.5.9

A vulnerability was discovered in Rancher 2.0.0 through the aforementioned patched versions, where a malicious Rancher user could craft an API request directed at the proxy for the Kubernetes API of a managed cluster to gain access to information they do not have access to. This is done by passing the “Impersonate-User” or “Impersonate-Group” header in the Connection header, which is then correctly removed by the proxy. At this point, instead of impersonating the user and their permissions, the request will act as if it was from the Rancher management server and incorrectly return the information. The vulnerability is limited to valid Rancher users with some level of permissions on the cluster. There is not a direct mitigation besides upgrading to the patched Rancher versions.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-31999
• https://bugzilla.suse.com/show_bug.cgi?id=1187084

Published to the GitHub Advisory Database

Apr 24, 2024

Last updated

Apr 24, 2024