A Reliance on Untrusted Inputs in a Security Decision vulnerability in Rancher allows users in the cluster to act as others users in the cluster by forging the "Impersonate-User" or "Impersonate-Group" headers. This issue affects: Rancher versions prior to 2.5.9. Rancher versions prior to 2.4.16.

A Incorrect Permission Assignment for Critical Resource vulnerability in Rancher allows users in the cluster to modify resources they should not have access to. This issue affects: Rancher versions prior to 2.5.9 ; Rancher versions prior to 2.4.16.

A Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Rancher allows remote attackers to execute JavaScript via malicious links. This issue affects: SUSE Rancher Rancher versions prior to 2.5.6.

Rancher 2 through 2.2.4 is vulnerable to a Cross-Site Websocket Hijacking attack that allows an exploiter to gain access to clusters managed by Rancher. The attack requires a victim to be logged into a Rancher server, and then to access a third-party site hosted by the exploiter. Once that is accomplished, the exploiter is able to execute commands against the cluster's Kubernetes API with the permissions and identity of the victim.

An issue was discovered that affects the following versions of Rancher: v2.0.0 through v2.0.13, v2.1.0 through v2.1.8, and v2.2.0 through 2.2.1. When Rancher starts for the first time, it creates a default admin user with a well-known password. After initial setup, the Rancher administrator may choose to delete this default admin user. If Rancher is restarted, the default admin user will be recreated with the well-known default password. An attacker could exploit this by logging in with the default admin credentials. This can be mitigated by deactivating the default admin user rather than completing deleting them.

A vulnerability exists in Rancher before 2.2.4 in the login component, where the errorMsg parameter can be tampered to display arbitrary content, filtering tags but not special characters or symbols. There's no other limitation of the message, allowing malicious users to lure legitimate users to visit phishing sites with scare tactics, e.g., displaying a "This version of Rancher is outdated, please visit https://malicious.rancher.site/upgrading" message.

In Rancher 2 through 2.2.3, Project owners can inject additional fluentd configuration to read files or execute arbitrary commands inside the fluentd container.

In Rancher 1 and 2 through 2.2.3, unprivileged users (if allowed to deploy nodes) can gain admin access to the Rancher management plane because node driver options intentionally allow posting certain data to the cloud. The problem is that a user could choose to post a sensitive file such as /root/.kube/config or /var/lib/rancher/management-state/cred/kubeconfig-system.yaml.

In Rancher 2.0.0 through 2.1.5, project members have continued access to create, update, read, and delete namespaces in a project after they have been removed from it.

An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.