Disabling all other default permissions of anonymous on mediawiki, except read permission.
In file LocalSettings.php:
$wgGroupPermissions[‘*’][‘edit’] = false;
$wgGroupPermissions[‘*’][‘writeapi’] = false;
$wgGroupPermissions[‘*’][‘createpage’] = false;
$wgGroupPermissions[‘*’][‘createtalk’] = false;
$wgGroupPermissions[‘*’][‘createaccount’] = false;