## Changes by Kind

### Bug or Regression

- CVE-2020-8557 (Medium): Node-local denial of service via container /etc/hosts file. See https://github.com/kubernetes/kubernetes/issues/93032 for more details. ([#92916](https://github.com/kubernetes/kubernetes/pull/92916), [@joelsmith](https://github.com/joelsmith)) [SIG Node]

func isHostIP(ipAddress string) bool {
	host, _, err := net.SplitHostPort(ipAddress)
	if err != nil {
		host = ipAddress
	}
	// Strip off IPv6 zone information.
	if i := strings.Index(host, "%"); i > -1 {
		host = host[:i]
	}
	return net.ParseIP(host) != nil
}

// extractHostPort - extracts host/port from many address formats

  - [Changelog since v1.21.4](#changelog-since-v1214)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access](#cve-2021-25741-symlink-exchange-can-allow-host-filesystem-access)
  - [Changes by Kind](#changes-by-kind-8)
    - [Feature](#feature-6)
    - [Bug or Regression](#bug-or-regression-8)

### Bug or Regression

- CVE-2020-8557 (Medium): Node-local denial of service via container /etc/hosts file. See https://github.com/kubernetes/kubernetes/issues/93032 for more details. ([#92916](https://github.com/kubernetes/kubernetes/pull/92916), [@joelsmith](https://github.com/joelsmith)) [SIG Node]

- Kubeadm: switch the preflight check (called 'Swap') that verifies if swap is enabled on Linux hosts to report a warning instead of an error. This is related to the graduation of the NodeSwap feature gate in the kubelet to Beta and being enabled by default in 1.23 - allows swap support on Linux hosts. In the next release of kubeadm (1.24) the preflight check will be removed, thus we recommend that you stop using it - e.g. via `--ignore-preflight-errors`...

        URL url1 = new URL(null, "smb://host/share", handler);
        URL url2 = new URL(null, "smb://host:1234/share/file.txt", handler);
        URL url3 = new URL(null, "smb://user:pass@host/share", handler);

        // Assert - Verify URL components
        assertEquals("smb", url1.getProtocol());
        assertEquals("host", url1.getHost());
        assertEquals(445, url1.getPort());

    public static final String LABELS_PERMISSIONS = "{labels.permissions}";

    /** The key of the message: Virtual Hosts */
    public static final String LABELS_virtual_hosts = "{labels.virtual_hosts}";

    /** The key of the message: Virtual Host */
    public static final String LABELS_virtual_host = "{labels.virtual_host}";

    /** The key of the message: Label */

- Images for cloud-controller-manager, kube-apiserver, kube-controller-manager, and kube-scheduler now contain a minimal /etc/nsswitch.conf and should respect /etc/hosts for lookups ([#69238](https://github.com/kubernetes/kubernetes/pull/69238), [@BenTheElder](https://github.com/BenTheElder))

### SIG Scheduling

    assertThat(parse("http:\\\\host/path"))
      .isEqualTo(parse("http://host/path"))
    assertThat(parse("http:///host/path"))
      .isEqualTo(parse("http://host/path"))
    assertThat(parse("http:\\//host/path"))
      .isEqualTo(parse("http://host/path"))
    assertThat(parse("http:/\\/host/path"))
      .isEqualTo(parse("http://host/path"))
    assertThat(parse("http://\\host/path"))

- Service Controller: will now update load balancer hosts after node's `ProviderID` is
  updated. ([#120492](https://github.com/kubernetes/kubernetes/pull/120492), [@cezarygerard](https://github.com/cezarygerard))