Revert back to using reg to get timezone

Reverts PR 51095
Checks for null characters

salt/modules/win_timezone.py

@@ -205,22 +205,23 @@ def get_zone():
     Returns:
         str: Timezone in unix format
 
-    Raises:
-        CommandExecutionError: If timezone could not be gathered
-
     CLI Example:
 
     .. code-block:: bash
 
         salt '*' timezone.get_zone
     '''
-    cmd = ['tzutil', '/g']
-    res = __salt__['cmd.run_all'](cmd, python_shell=False)
-    if res['retcode'] or not res['stdout']:
-        raise CommandExecutionError('tzutil encountered an error getting '
-                                    'timezone',
-                                    info=res)
-    return mapper.get_unix(res['stdout'].lower(), 'Unknown')
+    win_zone = __utils__['reg.read_value'](
+        hive='HKLM',
+        key='SYSTEM\\CurrentControlSet\\Control\\TimeZoneInformation',
+        vname='TimeZoneKeyName')['vdata']
+    # Some data may have null characters. We only need the first portion up to
+    # the first null character. See the following:
+    # https://github.com/saltstack/salt/issues/51940
+    # https://stackoverflow.com/questions/27716746/hklm-system-currentcontrolset-control-timezoneinformation-timezonekeyname-corrup
+    if '\0' in win_zone:
+        win_zone = win_zone.split('\0')[0]
+    return mapper.get_unix(win_zone.lower(), 'Unknown')
 
 
 def get_offset():