SQL 盲注 - 技术栈

SQL 盲注

江小白写bug2023-08-25 23:04

问题描述：

解决方案：

通过建立过滤器方法

添加拦截器：

web.xml 文件配置拦截器

XML 复制代码

    <filter>
        <filter-name>sqlFilter</filter-name>
        <filter-class>com.fh.filter.SqlFilter</filter-class>
    </filter>

java 复制代码

package com.fh.filter;

import com.fh.controller.base.BaseController;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;


public class SqlFilter extends BaseController implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void destroy() {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest)request;
        HttpServletResponse resp = (HttpServletResponse)response;
        PrintWriter writer = null;
        Enumeration params = req.getParameterNames();
        String sql = "";
        while(params.hasMoreElements()) {


            String name = params.nextElement().toString();
            String[] value = req.getParameterValues(name);
            for(int i=0;i<value.length;i++) {


                sql = sql+value[i];
            }
        }
        if(sqlValidate(sql)) {


            System.out.println("发现sql注入");
            response.setCharacterEncoding("GBK");
            writer = response.getWriter();
            writer.print("发现sql注入");
            return;
        }

        chain.doFilter(req,resp);
    }


    private boolean sqlValidate(String str) {


        str = str.toLowerCase();// 统一转为小写
        String badStr = "|exec|execute|insert|select|delete|update|drop|%|master|truncate|"
                + "declare|sitename|net user|xp_cmdshell|like|exec|execute|insert|create|drop|"
                + "table|grant|use|group_concat|column_name|information_schema.columns|table_schema|"
                + "select|delete|update|master|truncate|declare|-- |like|//|%";// 过滤掉的sql关键字，可以手动添加
        String[] badStrs = badStr.split("\\|");
        for (int i = 0; i < badStrs.length; i++) {


            if (str.indexOf(badStrs[i]) >= 0) {


                return true;
            }
        }
        return false;
    }


}