目录
uploa-labs-main
upload-labs-main第一关
前端防御
绕过前端防御
禁用js
Burpsuite抓包改包
upload-labs-main第二关
上传测试
错误类型
upload-labs-env
upload-labs-env第三关
上传测试
查看源码
解决方法
重命名,上传
upload-labs-env第四关
测试方法
上传文件
upload-labs-env第五关
代码解析
解题思路——大小写绕过
upload-labs-env第六关
代码
空格绕过
upload-labs-env第七关
代码
绕过
upload-labs-env第八关
::$DATA 绕过
upload-labs-env第九关
代码
思路
upload-labs-env第十关
代码
双写绕过
upload-labs第-env十一关
代码
思路——00截断问题(只存在于php5.2版本中)——get传参(url编码方式)
upload-labs-env第十二关
代码
思路——00截断——save_path是post传参
uploa-labs-main
upload-labs-main第一关
前端防御
有一个过滤函数checkFile()
绕过前端防御
禁用js
Chrome禁用js
设置—隐私与安全—网站设置—内容—JavaScript—不允许网站使用JavaScript
再次尝试上传,成功
Burpsuite抓包改包
首先为文件进行重命名,shell.php重命名为shell.jpg
上传shell.jpg文件
Burpsuite打开抓包
网页点击确定上传,
发送到重放器,改包,将shell.jpg改为shell.php,重新发送,上传成功
upload-labs-main第二关
上传测试
错误类型
文件类型不正确,
使用Burpsuite抓包改包
修改为image/png
上传成功
upload-labs-env
upload-labs-env第三关
上传测试
查看源码
$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists(UPLOAD_PATH)) {
$deny_ext = array('.asp','.aspx','.php','.jsp');//定义一个数组$deny_ext,包含不允许上传的文件扩展名
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);//删除文件名末尾的点
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext); //转换为小写
$file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
$file_ext = trim($file_ext); //首尾去空
if(!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];//获取上传文件的临时路径,文件在服务器上以临时文件的形式存储
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
if (move_uploaded_file($temp_file,$img_path)) {
$is_upload = true;
} else {
$msg = '上传出错!';
}
} else {
$msg = '不允许上传.asp,.aspx,.php,.jsp后缀文件!';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建!';
}
}
分析源码
需要绕过黑名单的过滤
.php3 、Phtml等都可以被解析
需要修改Apache的配置文件httpd.conf,使.php3 .phtml也可以被解析,当Apache和php版本低时,服务端可以修改
在配置文件中添加
AddType application/x-httpd-php .phtml
重启Apache
注意:在靶场实验中可能存在这个漏洞,真实项目中不会存在
解决方法
黑名单绕过
在upload-labs-env原版环境中,Apache的配置文件httpd.conf有将 .php3 .phtml解析成php文件
重命名,上传
上传成功
解析成功
upload-labs-env第四关
测试方法
需要.htaccess文件
我们下载upload-labs-env原版环境,自带phpstudy的低版本
在Apache的低版本中,如果在目录中上传一个.htaccess文件
AddType application/x-httpd-php .jpg
会将后来上传的jpg文件解析成php,shell代码得以执行
上传文件
解析成功
upload-labs-env第五关
代码解析
$is_upload = false;
$msg = null;
# isset - 检测变量是否已经声明并且不为空
# $_POST['submit'] - 表示表单中名为 submit 的按钮被点击
if (isset($_POST['submit'])) {
# file_exists — 检查文件或目录是否存在返回值为true或false
if (file_exists(UPLOAD_PATH)) {
# 定义一个数组 $deny_ext,包含一系列禁止上传的文件扩展名
$deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
# trim — 去除字符串首尾处的空白字符(或者其他字符)
# $_FILES['upload_file'] 是表单中 name="upload_file" 对应的上传文件信息
# 它包含以下常见字段:
# $_FILES['upload_file']['name']:上传文件的原始名称(如 example.jpg)。
# $_FILES['upload_file']['type']:上传文件的 MIME 类型(如 image/jpeg)。
# $_FILES['upload_file']['size']:上传文件的大小(以字节为单位)。
# $_FILES['upload_file']['tmp_name']:上传文件的临时存储路径。
# $_FILES['upload_file']['error']:与文件上传相关的任何错误代码
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);//删除文件名末尾的点
#strrchr — 查找指定字符在字符串中的最后一次出现的位置,返回从最后一个点开始到字符串末尾的部分
$file_ext = strrchr($file_name, '.');
#str_ireplace - 执行不区分大小写的字符串替换,在目标字符串中查找指定的子字符串(无视大小写),然后用另一个字符串替换它
$file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
$file_ext = trim($file_ext); //首尾去空
#in_array — 检查数组中是否存在某个值,检查数组$deny_ext中是否存在$file_ext
if (!in_array($file_ext, $deny_ext)) {
# $_FILES['upload_file']['tmp_name']:上传文件的临时存储路径。
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
#move_uploaded_file — 将上传的文件移动到新位置
if (move_uploaded_file($temp_file, $img_path)) {
$is_upload = true;
} else {
$msg = '上传出错!';
}
} else {
$msg = '此文件类型不允许上传!';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建!';
}
}
解题思路——大小写绕过
文件后缀大写绕过
上传.php文件
修改后缀名为.PHP
上传成功
解析执行
upload-labs-env第六关
代码
$deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
$file_name = $_FILES['upload_file']['name'];
$file_name = deldot($file_name);//删除文件名末尾的点
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext); //转换为小写
$file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
空格绕过
文件名后缀加空格绕过
upload-labs-env第七关
代码
$deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
$file_name = trim($_FILES['upload_file']['name']);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext); //转换为小写
$file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
$file_ext = trim($file_ext); //首尾去空
绕过
文件后缀名后加点
upload-labs-env第八关
::$DATA 绕过
upload-labs-env第九关
代码
没有对代码进行重命名拼接路径
$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists(UPLOAD_PATH)) {
$deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);//删除文件名末尾的点
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext); //转换为小写
$file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
$file_ext = trim($file_ext); //首尾去空
if (!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.$file_name;
if (move_uploaded_file($temp_file, $img_path)) {
$is_upload = true;
} else {
$msg = '上传出错!';
}
} else {
$msg = '此文件类型不允许上传!';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建!';
}
}
思路
deldot()函数从后向前检测,当检测到末尾的第一个点时会继续它的检测,但是遇到空格会停下来
更改文件名为 index.php. . 即.php点 空格 点
运行php时,首先删除文件名末尾的点,
...... ,
最后一步检查,去除最后的空格,
此时文件名为index.php.
上传到Windows环境中时,系统会将其视为一个没有扩展名的文件,
Windows会将 index.php.
解释为没有扩展名的文件,因为末尾的点会被忽略。文件的实际名称会变成 index.php
,但扩展名会被视为不存在
upload-labs-env第十关
代码
$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists(UPLOAD_PATH)) {
$deny_ext = array("php","php5","php4","php3","php2","html","htm","phtml","pht","jsp","jspa","jspx","jsw","jsv","jspf","jtml","asp","aspx","asa","asax","ascx","ashx","asmx","cer","swf","htaccess");
$file_name = trim($_FILES['upload_file']['name']);
$file_name = str_ireplace($deny_ext,"", $file_name);
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.$file_name;
if (move_uploaded_file($temp_file, $img_path)) {
$is_upload = true;
} else {
$msg = '上传出错!';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建!';
}
}
使用str_ireplace()函数寻找文件名中存在的黑名单字符串,将它替换成空(即将它删掉),可以使用双写绕过黑名单
双写绕过
upload-labs第-env十一关
代码
$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
$ext_arr = array('jpg','png','gif');
//$_FILES['upload_file']['name']:获取上传文件的原始文件名
//strrpos($_FILES['upload_file']['name'], "."):查找文件名中最后一个点(.)的位置
//substr(..., strrpos(...) + 1):从最后一个点的下一个字符开始截取,得到文件扩展名
$file_ext = substr($_FILES['upload_file']['name'],strrpos($_FILES['upload_file']['name'],".")+1);
if(in_array($file_ext,$ext_arr)){
//$_FILES['upload_file']['tmp_name']:获取上传文件的临时存储路径
$temp_file = $_FILES['upload_file']['tmp_name'];
//$_GET['save_path']:从 URL 参数中获取保存路径
//rand(10, 99):生成一个 10 到 99 之间的随机数
//date("YmdHis"):生成当前日期时间字符串,格式为 年月日时分秒
//最终路径格式:保存路径/随机数+时间戳.扩展名
$img_path = $_GET['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;
if(move_uploaded_file($temp_file,$img_path)){
$is_upload = true;
} else {
$msg = '上传出错!';
}
} else{
$msg = "只允许上传.jpg|.png|.gif类型文件!";
}
}
思路——00截断问题(只存在于php5.2版本中)——get传参(url编码方式)
在c语言中\0是结束符
php底层是运行c语言
使用\0使截断代码,使后面代码不再运行
使用的传递方式是urlcode传参,%00使用url解码后为空字符
当一个字符串中存在空字符的时候,在被解析的时候会导致空字符后面的字符被丢弃
当php代码运行到
$img_path = $_GET['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;
if(move_uploaded_file($temp_file,$img_path)){
时,路径变成了/upload/web.php 后面的连接字符都被丢弃了,
之后将文件上传文件index.jpg的文件内容移动到web.php中,这样恶意代码就可以被解析了
upload-labs-env第十二关
代码
$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
$ext_arr = array('jpg','png','gif');
$file_ext = substr($_FILES['upload_file']['name'],strrpos($_FILES['upload_file']['name'],".")+1);
if(in_array($file_ext,$ext_arr)){
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = $_POST['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;
if(move_uploaded_file($temp_file,$img_path)){
$is_upload = true;
} else {
$msg = "上传失败";
}
} else {
$msg = "只允许上传.jpg|.png|.gif类型文件!";
}
}
思路——00截断——save_path是post传参
0x00
是十六进制表示的空字符(ASCII 值为 0)
在web.php后面加一个空格,在Burpsuite的hex转换中,找到这个空格(十六进制空格的编码为20)
将其修改为十六进制的空字符表示00
修改后
发送