upload-labs靶场通关姿势（1-10）
Pass 01
绕过方法：js绕过
浏览按F12，找到限制文件类型的参数，修改为php即可上传。
源码分析
因为这里只是在前端对上传文件类型做了限制，所以只要在前端修改允许的类型或者禁用js即可上传木马。
Pass 02
绕过方法：修改content-type
利用Burp Suite代理截断功能，将content-type字段内容修改为image/jpeg或image/png或image/gif即可上传。
源码分析
$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists($UPLOAD_ADDR)) {
if (($_FILES['upload_file']['type'] == 'image/jpeg') || ($_FILES['upload_file']['type'] == 'image/png') || ($_FILES['upload_file']['type'] == 'image/gif')) {
if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
$img_path = $UPLOAD_ADDR . $_FILES['upload_file']['name'];
$is_upload = true;
}
} else {
$msg = '文件类型不正确，请重新上传！';
}
} else {
$msg = $UPLOAD_ADDR.'文件夹不存在,请手工创建！';
}
}这里只对content-type做了检测，所以将该字段修改为image/jpeg或image/png或image/gif即可绕过。
Pass 03
绕过方法：黑名单绕过
这关用了拓展名黑名单过滤，php拓展名自然也被过滤了，但php5没被过滤，所以可以上传拓展名为php5的木马。
源码分析
$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
if (file_exists($UPLOAD_ADDR)) {
$deny_ext = array('.asp','.aspx','.php','.jsp');
$file_name = trim($_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); //收尾去空
if(!in_array($file_ext, $deny_ext)) {
if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR. '/' . $_FILES['upload_file']['name'])) {
$img_path = $UPLOAD_ADDR .'/'. $_FILES['upload_file']['name'];
$is_upload = true;
}
} else {
$msg = '不允许上传.asp,.aspx,.php,.jsp后缀文件！';
}
} else {
$msg = $UPLOAD_ADDR . '文件夹不存在,请手工创建！';
}
}
?>这里用了黑名单过滤拓展名为.asp,.aspx,.php,.jsp的文件，但过滤不够全面，像php3、php5等这些拓展名还是可以上传的。
Pass 04
绕过方法：.htaccess绕过
先在本地新建一个内容为SetHandler application/x-httpd-php名为.htaccess的文件，然后上传到靶场。
再上传木马，利用burp suite把木马拓展名改为jpeg。
随后访问拓展名为jpeg的木马即可。
原理：.htaccess文件(或者”分布式配置文件”）提供了针对目录改变配置的方法， 即，在一个特定的文档目录中放置一个包含一个或多个指令的文件， 以作用于此目录及其所有子目录。SetHandler application/x-httpd-php的作用就是将该文件夹的所有文件都以php格式解析。
.htaccess参考链接：https://blog.csdn.net/wn314/article/details/77074477
源码分析
$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");
$file_name = trim($_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); //收尾去空
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 = '此文件不允许上传!';
}
} else {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}这里和pass 03一样，使用了黑名单过滤，这一次过滤相对比较全面，但没有过滤.htaccess文件，所以可以利用.htaccess绕过。
Pass 05
绕过方法：大小写绕过
把木马拓展名改成大小写混写的形式，即可成功上传木马。
源码分析
$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, '.');
$file_ext = str_ireplace('::$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'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$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！';
}
}这里像前面两关一样，用了黑名单过滤，而且这一次过滤的更加全面，连.htaccess都过滤了，但这里却没有将拓展名转化成小写，所以可以利用大小写绕过拓展名检测。
Pass 06
绕过方法：空格绕过
在文件名最后面加上一个空格，即可成功上传木马。
原理：在windows系统里空格命名是不被允许的，所以需要在burp之类里进行修改，木马成功上传后，会被windows系统自动去掉后面的点和空格，但要注意Unix/Linux系统没有这个特性。
源码分析
$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 = $_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
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！';
}
}这里相对前面两关没有对拓展名首尾去空格，所以，在拓展名后面加个空格，即可绕过黑名单的检测。
Pass 07
绕过方法：点绕过
在文件名最后面加上一个点，即可成功上传木马。
原理：在windows系统里拓展名不允许包括点和空格，所以需要在burp之类里进行修改，木马成功上传后，会被windows系统自动去掉后面的点和空格，但要注意Unix/Linux系统没有这个特性。
源码分析
$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']);
$file_ext = strrchr($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 {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}这里相对前面几关没有删除文件名末尾的点，所以，在拓展名后面加个点，即可绕过黑名单的检测。
Pass 08
绕过方法（：：$DATA绕过）
在文件名后面加上“::$DATA”，即可成功上传木马。
原理：在php+windows的情况下：如果文件名+"::$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。但要注意这个方法仅适用于Windows环境，Unix/Linux系统没有这个特性。
源码分析
$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
$file_ext = trim($file_ext); //首尾去空
if (!in_array($file_ext, $deny_ext)) {
$temp_file = $_FILES['upload_file']['tmp_name'];
$img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$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 {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
这里相对前面几关没有去除字符串::$DATA，所以，在拓展名后面加上::$DATA，即可绕过黑名单的检测。
Pass 09
绕过方法：点+空格+点绕过
在文件名后面加上“. .”（点+空格+点），即可成功上传木马。
源码分析
$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 {
$msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
}
}
这里对拓展名过滤得比较全面，黑名单类型全，大小写经过转换，去除了文件名末尾的点，去除了文件名尾空格，还去除了::$DATA。
但这里的代码顺序是，先去除文件名末尾的点，再删除文件名首尾的空格，都是只执行一次，对于“点+空格+点”，它只过滤了后面两个字符，还剩一个点，所以这里又回到了pass 07的点绕过。
Pass 10
绕过方法：双写绕过
双写拓展名，当其中一个被替换之后，还有一个保留，这样就可以成功上传木马了。
源码分析
$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！';
}
}
这里还是使用了黑名单过滤，而且还将黑名单里的拓展名替换为空且，但因为只替换了一次，所以可以用双写拓展名的方法绕过。
str_ireplace函数参考链接：https://www.runoob.com/php/func-string-str-ireplace.html
总结
pass 01是在前端对文件名做了检测，只需在前端修改或禁用js即可
pass 02是MIME type验证，修改content-type字段内容修改为image/jpeg或image/png或image/gif即可绕过，MIME type验证参考链接：https://blog.csdn.net/weixin_43079958/article/details/105353324
pass 03-10 都是用了黑名单对文件拓展名做了检测，跟据不同的情况想办法让拓展名绕过检测而且能在服务端被正常解析即可。