CHIYU TCP/IP Converter devices suffers from a crlf injection vulnerability. Versions affected include BF-430, BF-431, and BF-450M.
# Exploit Title: CHIYU TCP/IP Converter devices - CRLF injection
# Date: May 31 2021
# Exploit Author: sirpedrotavares
# Vendor Homepage: https://www.chiyu-tech.com/msg/msg88.html
# Software Link: https://www.chiyu-tech.com/category-hardware.html
# Version: BF-430, BF-431, and BF-450M TCP/IP Converter devices - all firmware versions < June 2021
# Tested on: BF-430, BF-431, and BF-450M
# Publication: https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks
Description: A CRLF injection vulnerability was found on BF-430, BF-431, and BF-450M TCP/IP Converter devices from CHIYU Technology Inc due to a lack of validation on the parameter redirect= available on multiple CGI components.
CVSS: Medium – CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
Affected parameter: redirect=Component: all the CGI components
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
Accept-Encoding: gzip, deflate
Authorization: Basic OmFkbWlu
HTTP/1.1 302 Found
Steps to reproduce:
1. Navigate to the vulnerable device
2. Make a GET request to all CGI components
3. Append the payload at the end of the vulnerable parameter (redirect )
4. Submit the request and observe payload execution
Mitigation: The latest version of the CHIYU firmware should be installed
to mitigate this vulnerability.