MODRET set_displaylogin(cmd_rec *cmd) {
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_VIRTUAL|CONF_GLOBAL|CONF_ANON);

  c = add_config_param_str(cmd->argv[0], 1, cmd->argv[1]);
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.