alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT Realtek SDK - Command Execution/Backdoor Access Inbound (CVE-2021-35395)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/formSysCmd"; fast_pattern; endswith; http.request_body; content:"sysCmd="; reference:url,www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain/; reference:cve,2021-35395; classtype:attempted-user; sid:2033839; rev:2; metadata:attack_target Server, created_at 2021_08_30, cve CVE_2021_35395, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, tag CISA_KEV, updated_at 2021_08_30, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;)