bug: change to more secure file permissions

Author: membphis

runner-core/src/main/java/org/apache/apisix/plugin/runner/server/ApplicationRunner.java

@@ -114,7 +114,7 @@ public void start(String path) throws Exception {
         try {
             initServerBootstrap(bootstrap);
             ChannelFuture future = bootstrap.bind(new DomainSocketAddress(path)).sync();
-            Runtime.getRuntime().exec("chmod 777 " + socketFile);
+            Runtime.getRuntime().exec("chmod 700 " + socketFile);
             logger.warn("java runner is listening on the socket file: {}", socketFile);
 
             future.channel().closeFuture().sync();