GBool DCTStream::readHeader() {
  GBool doScan;
  int n;
  int c = 0;
  int i;

  doScan = gFalse;
  while (!doScan) {
    c = readMarker();
    switch (c) {
    case 0xc0:			// SOF0 (sequential)
    case 0xc1:			// SOF1 (extended sequential)
      if (!readBaselineSOF()) {
	return gFalse;
      }
      break;
    case 0xc2:			// SOF2 (progressive)
      if (!readProgressiveSOF()) {
	return gFalse;
      }
      break;
    case 0xc4:			// DHT
      if (!readHuffmanTables()) {
	return gFalse;
      }
      break;
    case 0xd8:			// SOI
      break;
    case 0xd9:			// EOI
      return gFalse;
    case 0xda:			// SOS
      if (!readScanInfo()) {
	return gFalse;
      }
      doScan = gTrue;
      break;
    case 0xdb:			// DQT
      if (!readQuantTables()) {
	return gFalse;
      }
      break;
    case 0xdd:			// DRI
      if (!readRestartInterval()) {
	return gFalse;
      }
      break;
    case 0xe0:			// APP0
      if (!readJFIFMarker()) {
	return gFalse;
      }
      break;
    case 0xee:			// APP14
      if (!readAdobeMarker()) {
	return gFalse;
      }
      break;
    case EOF:
      error(errSyntaxError, getPos(), "Bad DCT header");
      return gFalse;
    default:
      if (c >= 0xe0) {
	n = read16() - 2;
	for (i = 0; i < n; ++i) {
	  str->getChar();
	}
      } else {
	error(errSyntaxError, getPos(), "Unknown DCT marker <{0:02x}>", c);
	return gFalse;
      }
      break;
    }
  }

  return gTrue;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.