diff --git a/src/gquic_process.cpp b/src/gquic_process.cpp
index 2f3ce62..107a47c 100644
--- a/src/gquic_process.cpp
+++ b/src/gquic_process.cpp
@@ -118,6 +118,12 @@ static int get_value(unsigned char *payload, int *offset, int len)
 	return 0;
 }
 
+
+static int check_length(int last_len, int field_len)
+{
+	return ((last_len-field_len>0) ? 1 : 0);
+}
+
 int quic_getLinkState(struct _quic_context *_context)
 {
 	UCHAR state = 0;
@@ -229,23 +235,39 @@ unsigned long long get_variable_length(char *p, int offset, int v_len)
 	return 0;
 }
 
-long long bit_to_value(char *payload, unsigned char flags, unsigned long long *out_value, int *used_len)
+long long bit_to_value(char *payload, int payload_len, unsigned char flags, unsigned long long *out_value, int *used_len)
 {
 	switch(flags&0x3) // packet number
 	{
 		case	0x3: // 6 bytes
+			if(!check_length(payload_len-*used_len, 6))
+			{
+				return -1;
+			}
 			*out_value=get_variable_length(payload, *used_len, 6);
 			*used_len+=6;
 			break;
 		case	0x2: // 4 bytes
+			if(!check_length(payload_len-*used_len, sizeof(unsigned int)))
+			{
+				return -1;
+			}
 			*out_value=(unsigned long long)ntohl(*(unsigned int *)(payload+*used_len));
 			*used_len+=4;
 			break;
 		case	0x1: // 2bytes
+			if(!check_length(payload_len-*used_len, sizeof(unsigned short)))
+			{
+				return -1;
+			}
 			*out_value=(unsigned long long)ntohs(*(unsigned short *)(payload+*used_len));
 			*used_len+=2;
 			break;
 		default:	// 1 byte
+			if(!check_length(payload_len-*used_len, sizeof(unsigned char)))
+			{
+				return -1;
+			}
 			*out_value=payload[*used_len];
 			*used_len+=1;
 			break;
@@ -268,23 +290,37 @@ int get_quic_tlv(char *start_pos, quic_tlv_t *tlv, int len, int type, int thread
 	return 0;
 }
 
-int get_stream_id(struct streaminfo *pstream, struct _quic_context* _context, char* payload, unsigned char frame_type, int *used_len)
+int get_stream_id(struct streaminfo *pstream, struct _quic_context* _context, char* payload, int payload_len, unsigned char frame_type, int *used_len)
 {
 	int stream_len=0,offset_len=0;
 
 	_context->quic_info.frame_hdr.frame_type=frame_type;
 	
 	stream_len=(frame_type&GQUIC_SPECIAL_FRAME_STREAM_ID)+1;
+	if(!check_length(payload_len-*used_len, stream_len))
+	{
+		return -1;
+	}
+		
 	_context->quic_info.frame_hdr.stream_id=(unsigned int)get_variable_length(payload, *used_len, stream_len);
 	*used_len+=stream_len;  // stream ID length
 
 	if(frame_type&GQUIC_SPECIAL_FRAME_STREAM_DLEN)
 	{
+		if(!check_length(payload_len-*used_len, 2))
+		{
+			return -1;
+		}
 		_context->quic_info.frame_hdr.data_len=ntohs(*(unsigned short *)(payload+*used_len));
 		*used_len+=2;  //data length
 	}
 			
 	offset_len=(frame_type&GQUIC_SPECIAL_FRAME_STREAM_OFFSET) ? (((frame_type&GQUIC_SPECIAL_FRAME_STREAM_OFFSET))>>2)+1 : 0;
+	if(!check_length(payload_len-*used_len, offset_len))
+	{
+		return -1;
+	}
+		
 	_context->quic_info.frame_hdr.offset=get_variable_length(payload, *used_len, offset_len);
 	*used_len+=offset_len;
 
@@ -325,6 +361,7 @@ unsigned long long get_packet_number(char* data, int offset, char pkn_len)
 // GQUIC version from 0 to 43
 static enum _QUIC_VERSION parse_q0to43_header(struct streaminfo *pstream, struct _quic_context* _context, char *payload, int payload_len, int *used_len)
 {
+	int ret=0;
 	char public_flags=0;
 	
 	struct _quic_public_header *gquic_hdr=&(_context->quic_info.quic_hdr);
@@ -380,8 +417,12 @@ static enum _QUIC_VERSION parse_q0to43_header(struct streaminfo *pstream, struct
 		return QUIC_VERSION_UNKNOWN;
 	}
 
-	bit_to_value(payload, gquic_hdr->public_flags>>4, &gquic_hdr->packet_number, used_len);
-			
+	ret=bit_to_value(payload, payload_len, gquic_hdr->public_flags>>4, &gquic_hdr->packet_number, used_len);
+	if(ret<0)
+	{
+		return (enum _QUIC_VERSION)gquic_hdr->quic_version;
+	}
+	
 	if(gquic_hdr->public_flags==GQUIC_PUBLIC_FLAG_NONCE)
 	{
 		*used_len+=32; //diversification nonce
@@ -520,8 +561,8 @@ enum _QUIC_VERSION is_quic_protocol(struct streaminfo *pstream, struct _quic_con
 				(quic_version==GQUIC_VERSION_T099) ||
 				(quic_version>=GQUIC_VERSION_Q047 && quic_version<=GQUIC_VERSION_Q050) ||
 				(quic_version>=GQUIC_VERSION_Q051 && quic_version<=GQUIC_VERSION_Q059) ||
-				(quic_version>=GQUIC_VERSION_T048&& quic_version<=GQUIC_VERSION_T049) ||
-				(quic_version>=GQUIC_VERSION_T050&& quic_version<=GQUIC_VERSION_T059) ||
+				(quic_version>=GQUIC_VERSION_T048 && quic_version<=GQUIC_VERSION_T049) ||
+				(quic_version>=GQUIC_VERSION_T050 && quic_version<=GQUIC_VERSION_T059) ||
 				(quic_version>=QUANT_VERSION_00 && quic_version<=QUANT_VERSION_FF) ||
 				(quic_version>=QUIC_GO_VERSION_00 && quic_version<=QUIC_GO_VERSION_FF) ||
 				(quic_version>=QUICLY_VERSION_00 && quic_version<=QUICLY_VERSION_FF) ||
@@ -647,55 +688,6 @@ int parse_extension_tag(struct streaminfo *pstream, struct _quic_stream **quic_s
 	return 0;
 }
 
-int gquic_frame_type_ack(struct streaminfo *pstream, struct _quic_context* _context, char *payload, int payload_len, int *used_len, char frame_type, void *a_packet)
-{
-	unsigned char num_timestamp;
-	unsigned char num_blocks=0;;
-	unsigned short largest_acked_delta_time=0;
-	unsigned long long ack_block_length=0;
-	unsigned long long largest_observed_ack=0;		
-
-	bit_to_value(payload, frame_type>>2, &largest_observed_ack, used_len);  // frame_type -> LL
-	largest_acked_delta_time=ntohs(*(unsigned short *)(payload+*used_len));
-	*used_len+=sizeof(unsigned short);
-
-	if(frame_type&0x20)	// frame_type -> n
-	{
-		num_blocks=(*(unsigned char *)(payload+*used_len))-1;
-	}
-	bit_to_value(payload, frame_type>>2, &ack_block_length, used_len); // frame_type -> mm
-
-	if(num_blocks>0)
-	{
-		*used_len+=1; //gap_to_next_block
-
-		*used_len+=(num_blocks*sizeof(unsigned int)); //Ack block length
-	}
-
-	num_timestamp=*(unsigned char *)(payload+*used_len);
-	*used_len += 1;
-	
-	if(num_timestamp > 0)
-	{
-		*used_len+=sizeof(unsigned char); //Delta Largest Observed
-		*used_len+= sizeof(unsigned int); //First Timestamp
-		*used_len+=(num_timestamp-1)*(1+2); //1+2=Delta Largest Observed+Time Since Previous Timestamp
-	}
-
-	MESA_handle_runtime_log(g_quic_param.logger,
-												RLOG_LV_DEBUG,
-												"QUIC_ACK",
-												"largest_observed_ack: %llu largest_acked_delta_time: %u num_blocks: %d ack_block_length: %d num_timestamp: %d addr: %s",
-												largest_observed_ack,
-												largest_acked_delta_time,
-												num_blocks,
-												ack_block_length,
-												num_timestamp,
-												printaddr(&pstream->addr, pstream->threadnum));
-
-	return 0;
-}
-
 int gquic_frame_type_stream(struct streaminfo *pstream, struct _quic_context* _context, char *payload, int payload_len, int *used_len, void *a_packet)
 {
 	int ret=0;
@@ -703,6 +695,11 @@ int gquic_frame_type_stream(struct streaminfo *pstream, struct _quic_context* _c
 	unsigned short tag_num = 0;
 	unsigned int message_tag;
 
+	if(!check_length(payload_len-*used_len, 8))
+	{
+		return state;
+	}
+	
 	message_tag=(unsigned int)ntohl(*(unsigned int *)(payload+*used_len));
 	*used_len+=4; 
 
@@ -762,6 +759,10 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 				return APP_STATE_GIVEME; // PADDING frame
 				break;
 			case	GQUIC_REGULAR_FRAME_RST_STREAM:
+				if(!check_length(payload_len-*used_len, sizeof(unsigned int)+sizeof(unsigned long long)+sizeof(unsigned int)))
+				{
+					return APP_STATE_GIVEME;
+				}
 				stream_id=(unsigned int)get_variable_length(payload, *used_len, sizeof(unsigned int));
 				*used_len+=sizeof(unsigned int);
 
@@ -783,12 +784,21 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 				return quic_callPlugins(pstream, _context, NULL, 0, QUIC_INTEREST_KEY_MASK, a_packet);
 				break;
 			case	GQUIC_REGULAR_FRAME_CONNECTION_CLOSE:
+				if(!check_length(payload_len-*used_len, sizeof(unsigned int)+sizeof(unsigned short)))
+				{
+					return APP_STATE_GIVEME;
+				}
 				error_code=(unsigned int)get_variable_length(payload, *used_len, sizeof(unsigned int));
 				*used_len+=sizeof(unsigned int);
 
 				reason_phrase_length=(unsigned short)get_variable_length(payload, *used_len, sizeof(unsigned short));
 				*used_len+=sizeof(unsigned short);
 
+				if(!check_length(payload_len-*used_len, reason_phrase_length))
+				{
+					return APP_STATE_GIVEME;
+				}
+
 				*used_len+=reason_phrase_length; // skip Reason Phrase
 
 				MESA_handle_runtime_log(g_quic_param.logger,
@@ -802,6 +812,10 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 				return quic_callPlugins(pstream, _context, NULL, 0, QUIC_INTEREST_KEY_MASK, a_packet);
 				break;
 			case	GQUIC_REGULAR_FRAME_GOAWAY:
+				if(!check_length(payload_len-*used_len, sizeof(unsigned int)+sizeof(unsigned int)+sizeof(unsigned short)))
+				{
+					return APP_STATE_GIVEME;
+				}
 				error_code=(unsigned int)get_variable_length(payload, *used_len, sizeof(unsigned int));
 				*used_len+=sizeof(unsigned int);
 
@@ -811,7 +825,11 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 
 				reason_phrase_length=(unsigned short)get_variable_length(payload, *used_len, sizeof(unsigned short));
 				*used_len+=sizeof(unsigned short);
-
+				
+				if(!check_length(payload_len-*used_len, reason_phrase_length))
+				{
+					return APP_STATE_GIVEME;
+				}
 				*used_len+=reason_phrase_length; // skip Reason Phrase
 
 				MESA_handle_runtime_log(g_quic_param.logger,
@@ -824,6 +842,10 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 										printaddr(&pstream->addr, pstream->threadnum));
 				break;
 			case	GQUIC_REGULAR_FRAME_WINDOW_UPDATE:
+				if(!check_length(payload_len-*used_len, sizeof(unsigned int)+sizeof(unsigned long long)))
+				{
+					return APP_STATE_GIVEME;
+				}
 				stream_id=(unsigned int)get_variable_length(payload, *used_len, sizeof(unsigned int));
 				*used_len+=sizeof(unsigned int);
 
@@ -839,6 +861,10 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 										printaddr(&pstream->addr, pstream->threadnum));
 				break;
 			case	GQUIC_REGULAR_FRAME_BLOCKED:
+				if(!check_length(payload_len-*used_len, sizeof(unsigned int)))
+				{
+					return APP_STATE_GIVEME;
+				}
 				stream_id=(unsigned int)get_variable_length(payload, *used_len, sizeof(unsigned int));
 				*used_len+=sizeof(unsigned int);
 
@@ -850,7 +876,11 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 										printaddr(&pstream->addr, pstream->threadnum));
 				break;
 			case	GQUIC_REGULAR_FRAME_STOP_WAITING:
-				bit_to_value(payload, _context->quic_info.quic_hdr.public_flags>>4, &least_unacked_delta, used_len);
+				ret=bit_to_value(payload, payload_len, _context->quic_info.quic_hdr.public_flags>>4, &least_unacked_delta, used_len);
+				if(ret<0)
+				{
+					return APP_STATE_GIVEME;
+				}
 
 				MESA_handle_runtime_log(g_quic_param.logger,
 										RLOG_LV_DEBUG,
@@ -864,14 +894,13 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 				 //The receiver of a PING frame simply needs to ACK the packet containing this frame
 				break;
 			default: //Regular Frame Types
-				if(frame_type&GQUIC_SPECIAL_FRAME_STREAM)
+				if(frame_type&GQUIC_SPECIAL_FRAME_STREAM || (frame_type&0xC0)==GQUIC_SPECIAL_FRAME_ACK)
 				{					
-					stream_id=get_stream_id(pstream, _context, payload, frame_type, used_len);
-					ret=gquic_frame_type_stream(pstream, _context, payload, payload_len, used_len, a_packet);
-				}
-				else if((frame_type&0xC0)==GQUIC_SPECIAL_FRAME_ACK) // high bit set 0; (frame_type: 01nullmmB)
-				{			
-					stream_id=get_stream_id(pstream, _context, payload, frame_type, used_len);
+					stream_id=get_stream_id(pstream, _context, payload, payload_len, frame_type, used_len);
+					if(stream_id<0)
+					{
+						return APP_STATE_GIVEME;
+					}
 					ret=gquic_frame_type_stream(pstream, _context, payload, payload_len, used_len, a_packet);
 				}
 				else if((frame_type&0xE0)==GQUIC_SPECIAL_FRAME_CONGEST_FB)  // high two bits set 0; (frame_type: 01nullmmB)
@@ -898,9 +927,10 @@ int gquic_proc_unencrypt(struct streaminfo *pstream, struct _quic_context* _cont
 //QUIC_DATA:is quic data pcap;QUIC_TRUE:is handshake pcap;QUIC_RETURN_DROPME:not quic protocol;
 int parse_gquic_Q046(struct streaminfo *pstream, struct _quic_context* _context, void *a_packet, char * payload, int payload_len, int *used_len)
 {
+	int stream_id=0;
 	int ret=APP_STATE_GIVEME;
 	unsigned char frame_type;
-		
+	
 	while(*used_len < payload_len)
 	{
 		frame_type=payload[*used_len];
@@ -908,7 +938,11 @@ int parse_gquic_Q046(struct streaminfo *pstream, struct _quic_context* _context,
 		
 		if(frame_type&IQUIC_FRAME_STREAM_HEX08)
 		{			
-			get_stream_id(pstream, _context, payload, frame_type, used_len);
+			stream_id=get_stream_id(pstream, _context, payload, payload_len, frame_type, used_len);
+			if(stream_id<0)
+			{
+				return APP_STATE_GIVEME;
+			}
 			ret=gquic_frame_type_stream(pstream, _context, payload, payload_len, used_len, a_packet);
 		}
 		else