long Segment::ParseCues(long long off, long long& pos, long& len) {
 if (m_pCues)
 return 0; // success

 if (off < 0)
 return -1;

 long long total, avail;

 const int status = m_pReader->Length(&total, &avail);

 if (status < 0) // error
 return status;

  assert((total < 0) || (avail <= total));

  pos = m_start + off;

 if ((total < 0) || (pos >= total))
 return 1; // don't bother parsing cues

 const long long element_start = pos;
 const long long segment_stop = (m_size < 0) ? -1 : m_start + m_size;

 if ((pos + 1) > avail) {
    len = 1;
 return E_BUFFER_NOT_FULL;
 }

 long long result = GetUIntLength(m_pReader, pos, len);

 if (result < 0) // error
 return static_cast<long>(result);

 if (result > 0) // underflow (weird)
 {
    len = 1;
 return E_BUFFER_NOT_FULL;
 }

 if ((segment_stop >= 0) && ((pos + len) > segment_stop))
 return E_FILE_FORMAT_INVALID;

 if ((pos + len) > avail)
 return E_BUFFER_NOT_FULL;

 const long long idpos = pos;

 const long long id = ReadID(m_pReader, idpos, len);

 if (id != 0x0C53BB6B) // Cues ID
 return E_FILE_FORMAT_INVALID;

  pos += len; // consume ID
  assert((segment_stop < 0) || (pos <= segment_stop));


 if ((pos + 1) > avail) {
    len = 1;
 return E_BUFFER_NOT_FULL;
 }

  result = GetUIntLength(m_pReader, pos, len);

 if (result < 0) // error
 return static_cast<long>(result);

 if (result > 0) // underflow (weird)
 {
    len = 1;
 return E_BUFFER_NOT_FULL;
 }

 if ((segment_stop >= 0) && ((pos + len) > segment_stop))
 return E_FILE_FORMAT_INVALID;

 if ((pos + len) > avail)
 return E_BUFFER_NOT_FULL;

 const long long size = ReadUInt(m_pReader, pos, len);

 if (size < 0) // error
 return static_cast<long>(size);

 if (size == 0) // weird, although technically not illegal
 return 1; // done

  pos += len; // consume length of size of element
  assert((segment_stop < 0) || (pos <= segment_stop));


 const long long element_stop = pos + size;

 if ((segment_stop >= 0) && (element_stop > segment_stop))
 return E_FILE_FORMAT_INVALID;

 if ((total >= 0) && (element_stop > total))
 return 1; // don't bother parsing anymore

  len = static_cast<long>(size);

 if (element_stop > avail)
 return E_BUFFER_NOT_FULL;

 const long long element_size = element_stop - element_start;

  m_pCues =
 new (std::nothrow) Cues(this, pos, size, element_start, element_size);
 if (m_pCues == NULL)
 return -1;

 return 0; // success
}

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.