diff --git a/kv_store/src/kvstore_common/kvstore_common.c b/kv_store/src/kvstore_common/kvstore_common.c
index 483a28e9b917a9fe7adbd59fe79d22e62c31998f..ce118960fdc23de6c9c6433142e581023614128b 100755
--- a/kv_store/src/kvstore_common/kvstore_common.c
+++ b/kv_store/src/kvstore_common/kvstore_common.c
@@ -45,6 +45,16 @@ boolean IsValidValue(const char* value, unsigned int len)
     return TRUE;
 }
 
+static boolean IsValidValueInner(const char* value, size_t* actualSize)
+{
+    size_t valueLen = strnlen(value, MAX_VALUE_LEN);
+    *actualSize = valueLen;
+    if (valueLen >= MAX_VALUE_LEN || valueLen == 0) {
+        return FALSE;
+    }
+    return TRUE;
+}
+
 boolean IsValidKey(const char* key)
 {
     if (key == NULL || !IsValidValue(key, MAX_KEY_LEN)) {
@@ -59,6 +69,21 @@ boolean IsValidKey(const char* key)
     return TRUE;
 }
 
+static boolean IsValidKeyInner(const char* key, size_t* actualSize)
+{
+    size_t keyLen = strnlen(key, MAX_KEY_LEN);
+    *actualSize = keyLen;
+    if (keyLen >= MAX_KEY_LEN || keyLen == 0) {
+        return FALSE;
+    }
+    for (size_t i = 0; i < keyLen; i++) {
+        if (!IsValidChar(key[i])) {
+            return FALSE;
+        }
+    }
+    return TRUE;
+}
+
 #ifdef FEATURE_KV_CACHE
 static void FreeItem(KvItem* item)
 {
@@ -106,15 +131,13 @@ void DeleteKVCache(const char* key)
 
 void AddKVCache(const char* key, const char* value, boolean isNew)
 {
-    if (key == NULL || value == NULL) {
+    size_t keyLen = 0;
+    size_t valueLen = 0;
+    if (key == NULL || value == NULL || !IsValidKeyInner(key, &keyLen) ||
+        !IsValidValueInner(value, &valueLen)) {
         return;
     }
 
-    size_t keyLen = strnlen(key, MAX_KEY_LEN);
-    size_t valueLen = strnlen(value, MAX_VALUE_LEN);
-    if ((keyLen >= MAX_KEY_LEN) || (valueLen >= MAX_VALUE_LEN)) {
-        return;
-    }
     if (isNew) {
         DeleteKVCache(key);
     }
@@ -168,11 +191,11 @@ int GetValueByCache(const char* key, char* value, unsigned int maxLen)
             return EC_FAILURE;
         }
     }
-    size_t valueLen = strnlen(item->value, MAX_VALUE_LEN);
-    if (valueLen >= MAX_VALUE_LEN) {
+
+    if (maxLen < MAX_VALUE_LEN) {
         return EC_FAILURE;
     }
-    if ((valueLen >= maxLen) || (strcpy_s(value, maxLen, item->value) != EOK)) {
+    if (strcpy_s(value, maxLen, item->value) != EOK) {
         return EC_FAILURE;
     }
     return EC_SUCCESS;