    private ModelAndView renameGroup(HttpServletRequest request, HttpServletResponse response) throws Exception {
        
        String oldName = request.getParameter("groupName");
        String newName = request.getParameter("newName");

        if (newName != null && newName.matches(".*[&<>\"`']+.*")) {
            throw new ServletException("Group ID must not contain any HTML markup.");
        }

        if (StringUtils.hasText(oldName) && StringUtils.hasText(newName)) {
            m_groupRepository.renameGroup(oldName, newName);
        }
        
        return listGroups(request, response);
    }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.