diff --git a/src/file_asf.c b/src/file_asf.c
index 8f96d2aa..a9a76503 100644
--- a/src/file_asf.c
+++ b/src/file_asf.c
@@ -66,24 +66,29 @@ struct asf_stream_prop_s {
   unsigned char stream_type[16];
 } __attribute__ ((gcc_struct, __packed__));
 
+static const char *extension_wma="wma";
+static const char *extension_wmv="wmv";
+
 static int header_check_asf(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
 {
   const struct asf_header_obj_s *hdr=(const struct asf_header_obj_s*)buffer;
-  unsigned int i;
-  const struct asf_file_prop_s *prop=(const struct asf_file_prop_s*)(hdr+1);
+  const char *extension=file_hint_asf.extension;
+  const unsigned int nbr_header_obj=le32(hdr->nbr_header_obj);
   uint64_t size=0;
   time_t time=0;
-  const char *extension=file_hint_asf.extension;
+  unsigned int i;
+  uint64_t offset_prop=sizeof(struct asf_header_obj_s);
   /* Header + File Properties + Stream Properties + Header Extension */
   if(le64(hdr->object_size)<30 ||
       le64(hdr->object_size)>buffer_size ||
-      le32(hdr->nbr_header_obj)<4)
+      nbr_header_obj<4)
     return 0;
   for(i=0;
-      i<le32(hdr->nbr_header_obj) &&
-      (const unsigned char *)prop+0x28 < buffer + buffer_size;
-      i++, prop=(const struct asf_file_prop_s *)((const char *)prop + le64(prop->object_size)))
+      i < nbr_header_obj && offset_prop + 0x28 < buffer_size;
+      i++)
   {
+    const struct asf_file_prop_s *prop=(const struct asf_file_prop_s*)&buffer[offset_prop];
+    const uint64_t object_size=le64(prop->object_size);
     // ASF_File_Properties_Object   // 8CABDCA1-A947-11CF-8EE4-00C00C205365
     // ASF_Stream_Properties_Object // B7DC0791-A9B7-11CF-8EE6-00C00C205365
     static const unsigned char asf_file_prop_id[16]= {
@@ -94,18 +99,20 @@ static int header_check_asf(const unsigned char *buffer, const unsigned int buff
       0x91, 0x07, 0xdc, 0xb7, 0xb7, 0xa9, 0xcf, 0x11,
       0x8e, 0xe6, 0x00, 0xc0, 0x0c, 0x20, 0x53, 0x65
     };
-    if(le64(prop->object_size) < 0x18)
+    if(object_size < 0x18)
     {
-      log_info("header_check_asf object_size too small %llu\n", (long long unsigned)le64(prop->object_size));
+      log_info("header_check_asf object_size too small %llu\n", (long long unsigned)object_size);
       return 0;
     }
+    if(object_size > 0x8000000000000000)
+      return 0;
     if(memcmp(prop->object_id, asf_file_prop_id, sizeof(asf_file_prop_id))==0)
     {
-      if(le64(prop->object_size) < 0x28)
-	return 0;
-      if(le64(prop->file_size) < sizeof(struct asf_header_obj_s) + sizeof(struct asf_file_prop_s))
+      if(object_size < 0x28)
 	return 0;
       size=le64(prop->file_size);
+      if(size < sizeof(struct asf_header_obj_s) + sizeof(struct asf_file_prop_s))
+	return 0;
       time=td_ntfs2utc(le64(prop->file_date));
     }
     else if(memcmp(prop->object_id, asf_stream_prop_s, sizeof(asf_stream_prop_s))==0)
@@ -117,25 +124,27 @@ static int header_check_asf(const unsigned char *buffer, const unsigned int buff
       const char wmv[16]={
 	0xc0, 0xef, 0x19, 0xbc, 0x4d, 0x5b, 0xcf, 0x11, 0xa8, 0xfd, 0x00, 0x80, 0x5f, 0x5c, 0x44, 0x2b
       };
-      if(le64(prop->object_size) < 0x28)
+      if(object_size < 0x28)
 	return 0;
       if(memcmp(stream->stream_type, wma, sizeof(wma))==0)
-	extension="wma";
+	extension=extension_wma;
       else if(memcmp(stream->stream_type, wmv, sizeof(wmv))==0)
-	extension="wmv";
+	extension=extension_wmv;
     }
-    if(le64(prop->object_size) > buffer_size)
-      break;
+    offset_prop+=object_size;
   }
+  if(size > 0 && size < offset_prop)
+    return 0;
   reset_file_recovery(file_recovery_new);
   file_recovery_new->extension=extension;
+  file_recovery_new->min_filesize=offset_prop;
+  file_recovery_new->time=time;
   if(size > 0)
   {
-    file_recovery_new->calculated_file_size=le64(size);
+    file_recovery_new->calculated_file_size=size;
     file_recovery_new->data_check=&data_check_size;
     file_recovery_new->file_check=&file_check_size;
   }
-  file_recovery_new->time=time;
   return 1;
 }