diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 8e7988188..5af71bef3 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1577,7 +1577,7 @@ void SimulateIso14443aTag(uint8_t tagType, uint16_t flags, uint8_t *data, uint8_
                 //   block1 = 4byte UID.
                 p_response = &responses[RESP_INDEX_UIDC1];
             } else { // all other tags (16 byte block tags)
-                uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
+                uint8_t emdata[MAX_MIFARE_FRAME_SIZE] = {0};
                 emlGetMemBt(emdata, block, 16);
                 AddCrc14A(emdata, 16);
                 EmSendCmd(emdata, sizeof(emdata));
@@ -1591,7 +1591,7 @@ void SimulateIso14443aTag(uint8_t tagType, uint16_t flags, uint8_t *data, uint8_
                 // send NACK 0x0 == invalid argument
                 EmSend4bit(CARD_NACK_IV);
             } else {
-                uint8_t emdata[MAX_FRAME_SIZE];
+                uint8_t emdata[MAX_FRAME_SIZE] = {0};
                 // first blocks of emu are header
                 int start = block1 * 4 + MFU_DUMP_PREFIX_LENGTH;
                 len   = (block2 - block1 + 1) * 4;
@@ -1675,7 +1675,7 @@ void SimulateIso14443aTag(uint8_t tagType, uint16_t flags, uint8_t *data, uint8_
                 // send NACK 0x0 == invalid argument
                 EmSend4bit(CARD_NACK_IV);
             } else {
-                uint8_t cmd[3];
+                uint8_t cmd[3] = {0,0,0};
                 cmd[0] = tearings[index];
                 AddCrc14A(cmd, sizeof(cmd) - 2);
                 EmSendCmd(cmd, sizeof(cmd));
@@ -1712,7 +1712,7 @@ void SimulateIso14443aTag(uint8_t tagType, uint16_t flags, uint8_t *data, uint8_
             LogTrace(receivedCmd, Uart.len, Uart.startTime * 16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime * 16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, true);
             p_response = NULL;
         } else if (receivedCmd[0] == MIFARE_ULEV1_AUTH && len == 7 && tagType == 7) { // NTAG / EV-1
-            uint8_t pwd[4];
+            uint8_t pwd[4] = {0,0,0,0};
             emlGetMemBt(pwd, (pages - 1) * 4 + MFU_DUMP_PREFIX_LENGTH, sizeof(pwd));
             if (g_dbglevel >= DBG_DEBUG) {
                 Dbprintf("Reader sent password: ");
@@ -1734,9 +1734,9 @@ void SimulateIso14443aTag(uint8_t tagType, uint16_t flags, uint8_t *data, uint8_
                 p_response = NULL;
                 EmSend4bit(CARD_NACK_IV);
             }
-            p_response = &responses[RESP_INDEX_PACK];
+
         } else if (receivedCmd[0] == MIFARE_ULEV1_VCSL && len == 23 && tagType == 7) {
-            uint8_t cmd[3];
+            uint8_t cmd[3] = {0,0,0};
             emlGetMemBt(cmd, (pages - 2) * 4 + 1 + MFU_DUMP_PREFIX_LENGTH, 1);
             AddCrc14A(cmd, sizeof(cmd) - 2);
             EmSendCmd(cmd, sizeof(cmd));