diff --git a/client/cmddata.c b/client/cmddata.c
index fa54d01a6..7d9ec1b76 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -556,7 +556,7 @@ int CmdManchesterDemod(const char *Cmd)
 
   /* But it does not work if compiling on WIndows: therefore we just allocate a */
   /* large array */
-  uint8_t BitStream[MAX_GRAPH_TRACE_LEN];
+  uint8_t BitStream[MAX_GRAPH_TRACE_LEN] = {0};
 
   /* Detect high and lows */
   for (i = 0; i < GraphTraceLen; i++)
diff --git a/client/cmdhf15.c b/client/cmdhf15.c
index cc61d2899..2239e9e46 100644
--- a/client/cmdhf15.c
+++ b/client/cmdhf15.c
@@ -535,7 +535,8 @@ int CmdHF15CmdRaw (const char *cmd) {
  */
 int prepareHF15Cmd(char **cmd, UsbCommand *c, uint8_t iso15cmd[], int iso15cmdlen) {
 	int temp;
-	uint8_t *req=c->d.asBytes, uid[8];
+	uint8_t *req=c->d.asBytes;
+	uint8_t uid[8] = {0};
 	uint32_t reqlen=0;
 
 	// strip
diff --git a/client/cmdhficlass.c b/client/cmdhficlass.c
index 7156b1188..d9af90441 100644
--- a/client/cmdhficlass.c
+++ b/client/cmdhficlass.c
@@ -502,6 +502,8 @@ int CmdHFiClassReader_Dump(const char *Cmd)
   SendCommand(&c);
   
   UsbCommand resp;
+  uint8_t key_sel[8] = {0};
+  uint8_t key_sel_p[8] = { 0 };
 
   if (WaitForResponseTimeout(CMD_ACK,&resp,4500)) {
         uint8_t isOK    = resp.arg[0] & 0xff;
@@ -520,8 +522,6 @@ int CmdHFiClassReader_Dump(const char *Cmd)
         {
             if(elite)
             {
-                uint8_t key_sel[8] = {0};
-                uint8_t key_sel_p[8] = { 0 };
                 //Get the key index (hash1)
                 uint8_t key_index[8] = {0};
 
diff --git a/client/cmdhfmf.c b/client/cmdhfmf.c
index b66aa3a6d..4b591f0f6 100644
--- a/client/cmdhfmf.c
+++ b/client/cmdhfmf.c
@@ -1004,6 +1004,16 @@ int CmdHF14AMfNested(const char *Cmd)
 
 int CmdHF14AMfChk(const char *Cmd)
 {
+	if (strlen(Cmd)<3) {
+		PrintAndLog("Usage:  hf mf chk <block number>|<*card memory> <key type (A/B/?)> [t] [<key (12 hex symbols)>] [<dic (*.dic)>]");
+		PrintAndLog("          * - all sectors");
+		PrintAndLog("card memory - 0 - MINI(320 bytes), 1 - 1K, 2 - 2K, 4 - 4K, <other> - 1K");
+		PrintAndLog("d - write keys to binary file\n");
+		PrintAndLog("      sample: hf mf chk 0 A 1234567890ab keys.dic");
+		PrintAndLog("              hf mf chk *1 ? t");
+		return 0;
+	}	
+
 	FILE * f;
 	char filename[256]={0};
 	char buf[13];
@@ -1021,6 +1031,7 @@ int CmdHF14AMfChk(const char *Cmd)
 	int transferToEml = 0;
 	int createDumpFile = 0;
 
+
 	keyBlock = calloc(stKeyBlock, 6);
 	if (keyBlock == NULL) return 1;
 
@@ -1047,15 +1058,6 @@ int CmdHF14AMfChk(const char *Cmd)
 		num_to_bytes(defaultKeys[defaultKeyCounter], 6, (uint8_t*)(keyBlock + defaultKeyCounter * 6));
 	}
 	
-	if (strlen(Cmd)<3) {
-		PrintAndLog("Usage:  hf mf chk <block number>|<*card memory> <key type (A/B/?)> [t] [<key (12 hex symbols)>] [<dic (*.dic)>]");
-		PrintAndLog("          * - all sectors");
-		PrintAndLog("card memory - 0 - MINI(320 bytes), 1 - 1K, 2 - 2K, 4 - 4K, <other> - 1K");
-		PrintAndLog("d - write keys to binary file\n");
-		PrintAndLog("      sample: hf mf chk 0 A 1234567890ab keys.dic");
-		PrintAndLog("              hf mf chk *1 ? t");
-		return 0;
-	}	
 	
 	if (param_getchar(Cmd, 0)=='*') {
 		blockNo = 3;
@@ -1144,11 +1146,11 @@ int CmdHF14AMfChk(const char *Cmd)
 					keycnt++;
 					memset(buf, 0, sizeof(buf));
 				}
+				fclose(f);
 			} else {
 				PrintAndLog("File: %s: not found or locked.", filename);
 				free(keyBlock);
 				return 1;
-			fclose(f);
 			}
 		}
 	}
@@ -1586,8 +1588,8 @@ int CmdHF14AMfEKeyPrn(const char *Cmd)
 int CmdHF14AMfCSetUID(const char *Cmd)
 {
 	uint8_t wipeCard = 0;
-	uint8_t uid[8];
-	uint8_t oldUid[8];
+	uint8_t uid[8] = {0};
+	uint8_t oldUid[8]= {0};
 	int res;
 
 	if (strlen(Cmd) < 1 || param_getchar(Cmd, 0) == 'h') {
diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index a7312d21b..a3674a6ca 100644
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -319,7 +319,7 @@ int CmdEM4x50Read(const char *Cmd)
       ++i;
     while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
       ++i;
-    if (j>(MAX_GRAPH_TRACE_LEN/64)) {
+    if (j>=(MAX_GRAPH_TRACE_LEN/64)) {
       break;
     }
     tmpbuff[j++]= i - start;
diff --git a/client/cmdlfhitag.c b/client/cmdlfhitag.c
index af61bd366..13f075f72 100644
--- a/client/cmdlfhitag.c
+++ b/client/cmdlfhitag.c
@@ -149,6 +149,7 @@ int CmdLFHitagSim(const char *Cmd) {
 		tag_mem_supplied = true;
 		if (fread(c.d.asBytes,48,1,pf) == 0) {
       PrintAndLog("Error: File reading error");
+      fclose(pf);
 			return 1;
     }
 		fclose(pf);
diff --git a/client/cmdmain.c b/client/cmdmain.c
index fa358fac8..77f1c373e 100644
--- a/client/cmdmain.c
+++ b/client/cmdmain.c
@@ -134,8 +134,9 @@ int getCommand(UsbCommand* response)
  */
 bool WaitForResponseTimeout(uint32_t cmd, UsbCommand* response, size_t ms_timeout) {
   
+  UsbCommand resp;
+
   if (response == NULL) {
-    UsbCommand resp;
     response = &resp;
   }
 
diff --git a/client/mifarehost.c b/client/mifarehost.c
index fe8b8b268..7633def36 100644
--- a/client/mifarehost.c
+++ b/client/mifarehost.c
@@ -296,7 +296,7 @@ static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 // variables
 char logHexFileName[200] = {0x00};
 static uint8_t traceCard[4096] = {0x00};
-static char traceFileName[20];
+static char traceFileName[200] = {0};
 static int traceState = TRACE_IDLE;
 static uint8_t traceCurBlock = 0;
 static uint8_t traceCurKey = 0;
diff --git a/client/nonce2key/crapto1.c b/client/nonce2key/crapto1.c
index 90f55ab4c..61215420f 100644
--- a/client/nonce2key/crapto1.c
+++ b/client/nonce2key/crapto1.c
@@ -544,8 +544,14 @@ lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8],
 
 	statelist = malloc((sizeof *statelist) << 21);	//how large should be? 
 	if(!statelist || !odd || !even)
+	{
+				free(statelist);
+				free(odd);
+				free(even);
                 return 0;
 
+	}
+
 	s = statelist;
 	for(o = odd; *o != -1; ++o)
 		for(e = even; *e != -1; ++e)