文件上传
基本概念
在可以进行文件上传的地方，如果服务端和客户端没有对上传的文件进行严格的验证和过滤，就可能导致恶意文件被上传，恶意文件又被称为webshell。webshell具有非常强大的功能，因此造成的危害也很大。
文件上传的题型和解题思路大概可以被以上两个图包含了
以upload-labs为例子讲解
环境准备
https://github.com/c0ny1/upload-labs
下载地址，然后放在PHPstudy/www下，即可开启我们文件上传的征程
一·前端JS检验绕过
源码分析
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| function checkFile() {
var file = document.getElementsByName('upload_file')[0].value;
if (file == null || file == "") {
alert("请选择要上传的文件!");
return false;
}
var allow_ext = ".jpg|.png|.gif";
var ext_name = file.substring(file.lastIndexOf("."));
if (allow_ext.indexOf(ext_name + "|") == -1) {
var errMsg = "该文件不允许上传，请上传" + allow_ext + "类型的文件,当前文件类型为：" + ext_name;
alert(errMsg);
return false;
}
}
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思路
1.通过修改js中的数据换成一个.php即可上传php文件
2.先上传正常的允许的图片，在bp抓包，修改成1.php
3.关闭JS，然后上传？ （呃，反正我Google是不行）
二·后端无验证
源码分析
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| $is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists(UPLOAD_PATH)) {
if (($_FILES['upload_file']['type'] == 'image/jpeg') || ($_FILES['upload_file']['type'] == 'image/png') || ($_FILES['upload_file']['type'] == 'image/gif')) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH . '/' . $_FILES['upload_file']['name']
if (move_uploaded_file($temp_file, $img_path)) {
$is_upload = true;
} else {
$msg = '上传出错！';
}
} else {
$msg = '文件类型不正确，请重新上传！';
}
} else {
$msg = UPLOAD_PATH.'文件夹不存在,请手工创建！';
}
}
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思路
1.白名单，限制后缀
2.上传正常图片
3.bp抓包修改phpinfo()
三·特殊后缀绕过验证
源码分析
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| $is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists(UPLOAD_PATH)) {
$deny_ext = array('.asp','.aspx','.php','.jsp');
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = str_ireplace('::$DATA', '', $file_ext);
$file_ext = trim($file_ext);
if(!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$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！';
}
}
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思路
1.黑名单(asp, jsp, aspx, php)
2.查看一下php的config
这里可以将.php 或者 .phtml的后缀文件当作php的文件来执行
3.因此可以上传.phtml的文件来绕过验证
##这里我的配置是自己去把注释符号删了，不然phtml无法绕过
##也可以在这里加上php3,php5等
浅谈对.htaccess的理解
简介
.htaccess是一个配置文件（分布式配置文件），里面存放着Apache服务器配置相关的指令
httpd.config我们很难修改，因此.htaccess就时它的衍生物，起着跟它一样的作用
当Apache Web Server检测到当前目录下有.htaccess文件时会执行它
.htaccess文件能够改变目录的配置文件，即在一个特定的文件中设置一条或者多条指令，能够作用与当前目录以及所有的子目录。
当用户所用的命令受限制时，管理员可以通过Apache的AllowOverride来进行设置
.htaccess的启动需要 AllowOverride All 才能使用
.htaccess的基本作用
1.URL重写、自定义错误页面
2.MIME类型配置
3.访问权限控制等
4.主要体现在伪静态的应用
5.图片防盗链
6.自定义404错误页面
7.阻止/允许特定IP/IP段
8.目录浏览与主页
9.禁止访问指定文件类型
10.文件密码保护
自定义404和重定向
通常访问不存在的页面会显示404 Not Found
但是我们通过.htaccess的设置即可显示我们自定义的404页面，以菜鸟的为例
方法：ErrorDocument 状态码 /路径
ErrorDocument 404 /error/404.html //404
Redirect /begin/1.php /begin/2.php //访问1.php重定向到2.php
文件访问权限
可以通过以下代码拒绝文件被访问
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| <Files 1.php>
order allow,deny
deny from all
</Files>
|
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| <Files 1.php>
order allow,deny
allow from all
</Files>
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| <Files 1.php>
order allow,deny
deny from 127.0.0.1
</Files>
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SetHandler
强制所有匹配的文件被一个指定的处理器处理
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| SetHandler application/x-httpd-php
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AddHandler
可以实现在文件拓展名与特定的处理器之间建立映射
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| AddHandler cgi-script .xxx
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AddType
可以将给定的文件拓展名映射到指定的内容类型
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| AddType application/x-httpd-php .png
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php_value
.htaccess 文件允许你能够控制某个用户从你的站点单词上传数据量的大小
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| php_value auto_prepend_file 1.txt 在主文件解析之前自动解析包含1.txt的内容
php_value auto_append_file 2.txt 在主文件解析后自动解析1.txt的内容
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php_flag
php_flag 用来设定布尔值的php配置指令
可以将engine设置为0，在本目录和子目录中关闭php解析，造成源码泄露
文件包含
当前目录php文件头引入/etc/passwd
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| php_value auto_append_file /etc/passwd
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使作用范围内的php文件在文件头/尾自动include指定文件，支持php伪协议，.htaccess可以设置
php_value include_path “xxx”将include()的默认路径改变。
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| php_value include_path "xxx"
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远程文件包含
allow_url_include必须为On
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| php_value auto_append_file http:
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伪协议
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| php_value auto_append_file data:
或
php_value auto_append_file data:
或
php_value auto_append_file "php://filter/convert.base64-decode/resource=shell.txt"
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四·htaccess利用
源码分析
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| $is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists(UPLOAD_PATH)) {
$deny_ext = array(".php",".php5",".php4",".php3",".php2",".php1",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".pHp1",".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",".ini");
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = str_ireplace('::$DATA', '', $file_ext);
$file_ext = trim($file_ext);
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 = '此文件不允许上传!';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
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思路
1.审计发现.htaccess没有被过滤
2.正常上传，然后抓包
3.修改.htaccess，引入application/x-httpd-php
4.然后写入一句话
5.访问即可
方法二
利用windows下的符号绕过
通过？？？ <<< >>>
注意观察
浅谈对.user.ini理解
.user.ini可以理解为php.ini
这里的利用就是
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| php_value auto_prepend_file 1.txt 在主文件解析之前自动解析包含1.txt的内容
php_value auto_append_file 2.txt 在主文件解析后自动解析1.txt的内容
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五·user.ini利用
源码分析
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| $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);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = str_ireplace('::$DATA', '', $file_ext);
$file_ext = trim($file_ext);
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！';
}
}
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思路
1.user.ini没有被过滤
2.上传正常图片，抓包
六·Php过滤不严谨
源码分析
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| $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",".ini");
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);
$file_ext = strrchr($file_name, '.');
$file_ext = str_ireplace('::$DATA', '', $file_ext);
$file_ext = trim($file_ext);
if (!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
if (move_uploaded_file($temp_file, $img_path)) {
$is_upload = true;
} else {
$msg = '上传出错！';
}
} else {
$msg = '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！';
}
}
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思路
1.发现.Php没有被过滤
七·首尾去空绕过
源码分析
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| $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",".ini");
$file_name = $_FILES['upload_file']['name'];
$file_name = deldot($file_name);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = str_ireplace('::$DATA', '', $file_ext);
if (!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
if (move_uploaded_file($temp_file,$img_path)) {
$is_upload = true;
} else {
$msg = '上传出错！';
}
} else {
$msg = '此文件不允许上传';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
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思路
1.与上一题发现少了首位去空
filename="1.php "（php后面有个空格）
八·.绕过
源码分析
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| $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",".ini");
$file_name = trim($_FILES['upload_file']['name']);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = str_ireplace('::$DATA', '', $file_ext);
$file_ext = trim($file_ext);
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 {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
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思路
1.点号没有被过滤
九·::$DATA绕过
源码分析
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| $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",".ini");
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = trim($file_ext);
if (!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
if (move_uploaded_file($temp_file, $img_path)) {
$is_upload = true;
} else {
$msg = '上传出错！';
}
} else {
$msg = '此文件类型不允许上传！';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
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思路
利用Windows特性
在window的时候如果文件名+”::$DATA”会把::$DATA之后的数据当成文件流处理,不会检测后缀名，且保持::$DATA之前的文件名，他的目的就是不检查后缀名
例如:”phpinfo.php::$DATA”Windows会自动去掉末尾的::$DATA变成”phpinfo.php”
1.::$DATA没有被过滤
十·利用过滤只过滤了一次
源码分析
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| $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",".ini");
$file_name = trim($_FILES['upload_file']['name']);
$file_name = deldot($file_name);
$file_ext = strrchr($file_name, '.');
$file_ext = strtolower($file_ext);
$file_ext = str_ireplace('::$DATA', '', $file_ext);
$file_ext = trim($file_ext);
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！';
}
}
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思路
1.deldot会删除末尾的点，但是遇到空格就会停止
2.然后利用第八关一样绕过
payload:767.php. .（两个点中间有个空格）
十一·双写绕过
源码分析
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| $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","ini");
$file_name = trim($_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！';
}
}
|
思路
在代码的第8行会发现，运用了ireplace，但是仅仅只用了一次
所以我们就可以双写绕过flag.pphphp
十二·%00截断
源码分析
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| $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 = $_GET['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;
if(move_uploaded_file($temp_file,$img_path)){
$is_upload = true;
} else {
$msg = '上传出错！';
}
} else{
$msg = "只允许上传.jpg|.png|.gif类型文件！";
}
}
|
原理：因为00代表结束符，所以会把00后面的所有字符删除
条件：PHP版本小于5.3.4，PHP的magic_quotes_gpc为OFF状态
思路
这道理要这么理解
1.首先我们的后缀必须为jpg,png,gif其中一种，因为这里用的是白名单
2.我们上传的文件的路径是我们可控的$_GET
因此可以用%00来截断第8行代码/以后的值
十三·POST 00截断
和上一题一样
只是在post中上传的%00要hex编码
用+号是为了找位置，2b为+的编码
把2b改为00即可
十四·图片马
源码分析
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| function getReailFileType($filename){
$file = fopen($filename, "rb");
$bin = fread($file, 2);
fclose($file);
$strInfo = @unpack("C2chars", $bin);
$typeCode = intval($strInfo['chars1'].$strInfo['chars2']);
$fileType = '';
switch($typeCode){
case 255216:
$fileType = 'jpg';
break;
case 13780:
$fileType = 'png';
break;
case 7173:
$fileType = 'gif';
break;
default:
$fileType = 'unknown';
}
return $fileType;
}
$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
$temp_file = $_FILES['upload_file']['tmp_name'];
$file_type = getReailFileType($temp_file);
if($file_type == 'unknown'){
$msg = "文件未知，上传失败！";
}else{
$img_path = UPLOAD_PATH."/".rand(10, 99).date("YmdHis").".".$file_type;
if(move_uploaded_file($temp_file,$img_path)){
$is_upload = true;
} else {
$msg = "上传出错！";
}
}
}
|
思路
直接抓包修改为GIF89A
然后再上传
十五·getimgsize()
同上题一样的解法
getimgsize（）是一个得到图片长宽等信息的，也是判断是否为图片
十六·exif_imagetype
同上题一样解法
十七·二次渲染
源码分析
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| $is_upload = false;
$msg = null;
if (isset($_POST['submit'])){
$filename = $_FILES['upload_file']['name'];
$filetype = $_FILES['upload_file']['type'];
$tmpname = $_FILES['upload_file']['tmp_name'];
$target_path=UPLOAD_PATH.'/'.basename($filename);
$fileext= substr(strrchr($filename,"."),1);
if(($fileext == "jpg") && ($filetype=="image/jpeg")){
if(move_uploaded_file($tmpname,$target_path)){
$im = imagecreatefromjpeg($target_path);
if($im == false){
$msg = "该文件不是jpg格式的图片！";
@unlink($target_path);
}else{
srand(time());
$newfilename = strval(rand()).".jpg";
$img_path = UPLOAD_PATH.'/'.$newfilename;
imagejpeg($im,$img_path);
@unlink($target_path);
$is_upload = true;
}
} else {
$msg = "上传出错！";
}
}else if(($fileext == "png") && ($filetype=="image/png")){
if(move_uploaded_file($tmpname,$target_path)){
$im = imagecreatefrompng($target_path);
if($im == false){
$msg = "该文件不是png格式的图片！";
@unlink($target_path);
}else{
srand(time());
$newfilename = strval(rand()).".png";
$img_path = UPLOAD_PATH.'/'.$newfilename;
imagepng($im,$img_path);
@unlink($target_path);
$is_upload = true;
}
} else {
$msg = "上传出错！";
}
}else if(($fileext == "gif") && ($filetype=="image/gif")){
if(move_uploaded_file($tmpname,$target_path)){
$im = imagecreatefromgif($target_path);
if($im == false){
$msg = "该文件不是gif格式的图片！";
@unlink($target_path);
}else{
srand(time());
$newfilename = strval(rand()).".gif";
$img_path = UPLOAD_PATH.'/'.$newfilename;
imagegif($im,$img_path);
@unlink($target_path);
$is_upload = true;
}
} else {
$msg = "上传出错！";
}
}else{
$msg = "只允许上传后缀为.jpg|.png|.gif的图片文件！";
}
}
|
gif绕过
目前只找了gif的绕过方式
先上传正常的gif然后把上传后的gif与上传之前的gif用编辑器打开找相同的地方，然后写入我们的木马
我这里就是相同的地方，然后改成了我的Phpinfo
十八·十九·条件竞争
源码分析
没竞争出来
二十·
源码分析
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| $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 = $_POST['save_name'];
$file_ext = pathinfo($file_name,PATHINFO_EXTENSION);
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 = '禁止保存为该类型文件！';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
|
思路
没有对上传的文件做判断，只对用户输入的文件名做判断
后缀名黑名单
上传的文件名用户可控
黑名单用于用户输入的文件后缀名进行判断
move_uploaded_file()还有这么一个特性，会忽略掉文件末尾的 /.
这里直接上图
参考
https://www.cnblogs.com/sijidou/p/10856450.html
https://blog.csdn.net/solitudi/article/details/116666720
https://www.freebuf.com/articles/web/328241.html
https://ca01h.top/Web_security/basic_learning/16.%E6%96%87%E4%BB%B6%E4%B8%8A%E4%BC%A0%E6%BC%8F%E6%B4%9E%E5%88%A9%E7%94%A8
