diff --git a/Control.go b/Control.go
index 3f04cde..f4f9f6f 100644
--- a/Control.go
+++ b/Control.go
@@ -15,6 +15,8 @@ const CONTROL_FINISH = 0x05
 
 const CONTROL_FIELD_CONTENT_TYPE = 0x01
 
+const CONTROL_FRAME_LENGTH_MAX = 512
+
 type ControlFrame struct {
 	ControlType  uint32
 	ContentTypes [][]byte
@@ -75,6 +77,14 @@ func (c *ControlFrame) Decode(r io.Reader) (err error) {
 		return
 	}
 
+	if cflen > CONTROL_FRAME_LENGTH_MAX {
+		return ErrDecode
+	}
+
+	if cflen < 4 {
+		return ErrDecode
+	}
+
 	err = binary.Read(r, binary.BigEndian, &c.ControlType)
 	if err != nil {
 		return