diff --git a/MdeModulePkg/Universal/HiiDatabaseDxe/Database.c b/MdeModulePkg/Universal/HiiDatabaseDxe/Database.c
index 3d70207952..b1a3374991 100644
--- a/MdeModulePkg/Universal/HiiDatabaseDxe/Database.c
+++ b/MdeModulePkg/Universal/HiiDatabaseDxe/Database.c
@@ -2556,7 +2556,7 @@ ExportPackageList (
   UINTN                               ResultSize;
   EFI_HII_PACKAGE_HEADER              EndofPackageList;
 
-  ASSERT (Private != NULL || PackageList != NULL || UsedSize != NULL);
+  ASSERT (Private != NULL && PackageList != NULL && UsedSize != NULL);
   ASSERT (Private->Signature == HII_DATABASE_PRIVATE_DATA_SIGNATURE);
   ASSERT (IsHiiHandleValid (Handle));
 
diff --git a/MdeModulePkg/Universal/HiiDatabaseDxe/Font.c b/MdeModulePkg/Universal/HiiDatabaseDxe/Font.c
index 06b09e7f76..82f47163b7 100644
--- a/MdeModulePkg/Universal/HiiDatabaseDxe/Font.c
+++ b/MdeModulePkg/Universal/HiiDatabaseDxe/Font.c
@@ -1566,6 +1566,7 @@ HiiStringToImage (
   Status        = EFI_SUCCESS;
   StringIn2     = NULL;
   SystemDefault = NULL;
+  StringIn      = NULL;
 
   //
   // Calculate the string output information, including specified color and font .
@@ -1596,11 +1597,13 @@ HiiStringToImage (
       Foreground  = ((EFI_FONT_DISPLAY_INFO *) StringInfo)->ForegroundColor;
       Background  = ((EFI_FONT_DISPLAY_INFO *) StringInfo)->BackgroundColor;
 
-    } else {
+    } else if (Status == EFI_SUCCESS) {
       FontInfo   = &StringInfoOut->FontInfo;
       Height     = StringInfoOut->FontInfo.FontSize;
       Foreground = StringInfoOut->ForegroundColor;
       Background = StringInfoOut->BackgroundColor;
+    } else {
+      goto Exit;
     }
   }
 
@@ -1609,7 +1612,6 @@ HiiStringToImage (
   //
 
   StringPtr = String;
-  StringIn  = NULL;
 
   //
   // Ignore line-break characters only. Hyphens or dash character will be displayed
diff --git a/MdeModulePkg/Universal/HiiDatabaseDxe/String.c b/MdeModulePkg/Universal/HiiDatabaseDxe/String.c
index 8c207f9476..64148fe131 100644
--- a/MdeModulePkg/Universal/HiiDatabaseDxe/String.c
+++ b/MdeModulePkg/Universal/HiiDatabaseDxe/String.c
@@ -124,7 +124,7 @@ ConvertToUnicodeText (
   ASSERT (StringSrc != NULL && BufferSize != NULL);
 
   StringSize = AsciiStrSize (StringSrc) * 2;
-  if (*BufferSize < StringSize) {
+  if (*BufferSize < StringSize || StringDest == NULL) {
     *BufferSize = StringSize;
     return EFI_BUFFER_TOO_SMALL;
   }