CSI Service Account Token feature moves to Beta in 1.21. This feature improves the security posture and allows CSI drivers to receive pods' [bound service account tokens](https://github.com/kubernetes/enhancements/blob/master/keps/sig-auth/1205-bound-service-account-tokens/README.md). This feature also provides a knob to re-publish volumes so that short-lived volumes can be refreshed.

### CSI Health Monitoring

* The minimum supported go is the same as for v1.10: go1.9.1. ([#55301](https://github.com/kubernetes/kubernetes/pull/55301))
* CNI is the same as v1.10: v0.6.0 ([#51250](https://github.com/kubernetes/kubernetes/pull/51250))
* CSI is updated to 0.3.0 as compared to 0.2.0 in v1.10. ([#64719](https://github.com/kubernetes/kubernetes/pull/64719))

* Update golang/x/net dependency to bring in fixes for CVE-2019-9512, CVE-2019-9514 ([#81394](https://github.com/kubernetes/kubernetes/pull/81394), [@cblecker](https://github.com/cblecker))
* Fixes CVE-2019-11250: client-go header logging (at verbosity levels >= 7) now masks `Authorization` header contents ([#81330](https://github.com/kubernetes/kubernetes/pull/81330), [@tedyu](https://github.com/tedyu))

- The kubelet_runtime_operations_duration_seconds metric got additional buckets of 60, 300, 600, 900 and 1200 seconds ([#96054](https://github.com/kubernetes/kubernetes/pull/96054), [@alvaroaleman](https://github.com/alvaroaleman)) [SIG Instrumentation and Node]

- Metric buckets for `pod_start_duration_seconds` were changed to `{0.5, 1, 2, 3, 4, 5, 6, 8, 10, 20, 30, 45, 60, 120, 180, 240, 300, 360, 480, 600, 900, 1200, 1800, 2700, 3600}`. ([#120680](https://github.com/kubernetes/kubernetes/pull/120680), [@ruiwen-zhao](https://github.com/ruiwen-zhao))

* kubeadm deb/rpm packages: cAdvisor doesn't listen on `0.0.0.0:4194` without authentication/authorization because of the possible information leakage. The cAdvisor API can still be accessed via `https://{node-ip}:10250/stats/`, though. ([kubernetes/release#356](https://github.com/kubernetes/release/pull/356), [@luxas](https://github.com/luxas))


### Cloud Providers