bool extractPages (const char *srcFileName, const char *destFileName) {
  char pathName[4096];
  GooString *gfileName = new GooString (srcFileName);
  PDFDoc *doc = new PDFDoc (gfileName, NULL, NULL, NULL);

  if (!doc->isOk()) {
    error(errSyntaxError, -1, "Could not extract page(s) from damaged file ('{0:s}')", srcFileName);
    return false;
  }

  if (firstPage == 0 && lastPage == 0) {
    firstPage = 1;
    lastPage = doc->getNumPages();
  }
  if (lastPage == 0)
    lastPage = doc->getNumPages();
  if (firstPage == 0)
   if (firstPage == 0)
     firstPage = 1;
   if (firstPage != lastPage && strstr(destFileName, "%d") == NULL) {
    error(errSyntaxError, -1, "'{0:s}' must contain '%%d' if more than one page should be extracted", destFileName);
     return false;
   }
   for (int pageNo = firstPage; pageNo <= lastPage; pageNo++) {
     snprintf (pathName, sizeof (pathName) - 1, destFileName, pageNo);
     GooString *gpageName = new GooString (pathName);
	{
	  printUsage ("pdfseparate", "<PDF-sourcefile> <PDF-pattern-destfile>",
		      argDesc);
	}
      if (printVersion || printHelp)
	exitCode = 0;
      goto err0;
    }
  globalParams = new GlobalParams();
  ok = extractPages (argv[1], argv[2]);
  if (ok) {
    exitCode = 0;
  }
  delete globalParams;

err0:

  return exitCode;
}

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.