供求信息网站开发背景,北碚区建设银行网站,做展馆好的设计网站,前端设计是什么意思什么是文件上传漏洞#xff1f; 黑客利用文件上传后服务器解析处理文件的漏洞上传一个可执行的脚本文件#xff0c;并通过此脚本文件获得了执行服务器端命令的能力。 造成文件上传漏洞的原因: 1.服务器配置不当 2.开源编辑器上传漏洞 3.本地文件上传限制被绕过 4.过滤不严格被…
什么是文件上传漏洞 黑客利用文件上传后服务器解析处理文件的漏洞上传一个可执行的脚本文件并通过此脚本文件获得了执行服务器端命令的能力。 造成文件上传漏洞的原因: 1.服务器配置不当 2.开源编辑器上传漏洞 3.本地文件上传限制被绕过 4.过滤不严格被绕过 5.文件解析漏洞导致文件执行 6.文件路径截断 pikachu靶场-Unsafe Upfileupload_打开pikachu平台中的 unsafe upfileupload 客户端check,上传其他格式文-CSDN博客具体操作请看这篇文章
low等级
?phpif( isset( $_POST[ Upload ] ) ) {// Where are we going to be writing to?$target_path DVWA_WEB_PAGE_TO_ROOT . hackable/uploads/;$target_path . basename( $_FILES[ uploaded ][ name ] );// Can we move the file to the upload folder?if( !move_uploaded_file( $_FILES[ uploaded ][ tmp_name ], $target_path ) ) {// No$html . preYour image was not uploaded./pre;}else {// Yes!$html . pre{$target_path} succesfully uploaded!/pre;}
}?php basename()函数给出一个包含有指向一个文件的全路径的字符串本函数返回基本的文件名。 只是实现一个无任何过滤和验证直接上传文件即可 medium等级
?phpif( isset( $_POST[ Upload ] ) ) {// Where are we going to be writing to?$target_path DVWA_WEB_PAGE_TO_ROOT . hackable/uploads/;$target_path . basename( $_FILES[ uploaded ][ name ] );// File information$uploaded_name $_FILES[ uploaded ][ name ];$uploaded_type $_FILES[ uploaded ][ type ];$uploaded_size $_FILES[ uploaded ][ size ];// Is it an image?if( ( $uploaded_type image/jpeg || $uploaded_type image/png ) ( $uploaded_size 100000 ) ) {// Can we move the file to the upload folder?if( !move_uploaded_file( $_FILES[ uploaded ][ tmp_name ], $target_path ) ) {// No$html . preYour image was not uploaded./pre;}else {// Yes!$html . pre{$target_path} succesfully uploaded!/pre;}}else {// Invalid file$html . preYour image was not uploaded. We can only accept JPEG or PNG images./pre;}
}?获取用户上传文件的名称、类型和大小信息。通过文件类型限定只能上传图片限制了大小100000b。 抓包后修改后缀名即可绕过检测
high等级
?phpif( isset( $_POST[ Upload ] ) ) {// Where are we going to be writing to?$target_path DVWA_WEB_PAGE_TO_ROOT . hackable/uploads/;$target_path . basename( $_FILES[ uploaded ][ name ] );// File information$uploaded_name $_FILES[ uploaded ][ name ];$uploaded_ext substr( $uploaded_name, strrpos( $uploaded_name, . ) 1);$uploaded_size $_FILES[ uploaded ][ size ];$uploaded_tmp $_FILES[ uploaded ][ tmp_name ];// Is it an image?if( ( strtolower( $uploaded_ext ) jpg || strtolower( $uploaded_ext ) jpeg || strtolower( $uploaded_ext ) png ) ( $uploaded_size 100000 ) getimagesize( $uploaded_tmp ) ) {// Can we move the file to the upload folder?if( !move_uploaded_file( $uploaded_tmp, $target_path ) ) {// No$html . preYour image was not uploaded./pre;}else {// Yes!$html . pre{$target_path} succesfully uploaded!/pre;}}else {// Invalid file$html . preYour image was not uploaded. We can only accept JPEG or PNG images./pre;}
}?getimagesize() 函数用于获取图像大小及相关信息成功返回一个数组失败则返回 FALSE 并产生一条 E_WARNING 级的错误信息。 getimagesize() 函数将测定任何 GIFJPGPNGSWFSWCPSDTIFFBMPIFFJP2JPXJB2JPCXBM 或 WBMP 图像文件的大小并返回图像的尺寸以及文件类型及图片高度与宽度。 move_uploaded_filefile,newlocal 函数表示把给定的文件移动到新的位置 上传文件名为file.jpg且文件内容为?php eval($_POST[hacker]);?此时页面将报错显示上传失败因为getimagesize()函数判断该文件不是有效的图片文件所以需要在文件中加入文件头GIF89a。
也可制作图片马进行绕过具体教程在pikachu靶场处已经写明
impossible等级
?phpif( isset( $_POST[ Upload ] ) ) {// Check Anti-CSRF tokencheckToken( $_REQUEST[ user_token ], $_SESSION[ session_token ], index.php );// File information$uploaded_name $_FILES[ uploaded ][ name ];$uploaded_ext substr( $uploaded_name, strrpos( $uploaded_name, . ) 1);$uploaded_size $_FILES[ uploaded ][ size ];$uploaded_type $_FILES[ uploaded ][ type ];$uploaded_tmp $_FILES[ uploaded ][ tmp_name ];// Where are we going to be writing to?$target_path DVWA_WEB_PAGE_TO_ROOT . hackable/uploads/;//$target_file basename( $uploaded_name, . . $uploaded_ext ) . -;$target_file md5( uniqid() . $uploaded_name ) . . . $uploaded_ext;$temp_file ( ( ini_get( upload_tmp_dir ) ) ? ( sys_get_temp_dir() ) : ( ini_get( upload_tmp_dir ) ) );$temp_file . DIRECTORY_SEPARATOR . md5( uniqid() . $uploaded_name ) . . . $uploaded_ext;// Is it an image?if( ( strtolower( $uploaded_ext ) jpg || strtolower( $uploaded_ext ) jpeg || strtolower( $uploaded_ext ) png ) ( $uploaded_size 100000 ) ( $uploaded_type image/jpeg || $uploaded_type image/png ) getimagesize( $uploaded_tmp ) ) {// Strip any metadata, by re-encoding image (Note, using php-Imagick is recommended over php-GD)if( $uploaded_type image/jpeg ) {$img imagecreatefromjpeg( $uploaded_tmp );imagejpeg( $img, $temp_file, 100);}else {$img imagecreatefrompng( $uploaded_tmp );imagepng( $img, $temp_file, 9);}imagedestroy( $img );// Can we move the file to the web root from the temp folder?if( rename( $temp_file, ( getcwd() . DIRECTORY_SEPARATOR . $target_path . $target_file ) ) ) {// Yes!$html . prea href{$target_path}{$target_file}{$target_file}/a succesfully uploaded!/pre;}else {// No$html . preYour image was not uploaded./pre;}// Delete any temp filesif( file_exists( $temp_file ) )unlink( $temp_file );}else {// Invalid file$html . preYour image was not uploaded. We can only accept JPEG or PNG images./pre;}
}// Generate Anti-CSRF token
generateSessionToken();?imagecreatefromjpeg(filename) 从给定的文件或url中创建一个新的图片 imagejpeg(image,filename,quality) 从image图像中以 filename 文件名创建一个jpeg的图片参数quality可选0-100 (质量从小到大) imagedestroy(image) 销毁图像 Impossible级别的代码对上传文件进行了重命名为md5值导致%00截断无法绕过过滤规则加入Anti-CSRF token防护CSRF攻击对上传的图片文件进行重新编码以去除任何元数据在文件移动后删除任何临时文件确保不会留下无用文件导致攻击者无法上传含有恶意脚本的文件。
