long Tags::Tag::ParseSimpleTag(IMkvReader* pReader, long long pos,
 long long size) {
 if (!ExpandSimpleTagsArray())
 return -1;

 SimpleTag& st = m_simple_tags[m_simple_tags_count++];
  st.Init();

 return st.Parse(pReader, pos, size);
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.