alert http1 any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT SonicWall SMA Authenticated Command Injection Attempt CVE-2021-20039"; flow:established,to_server; http.request_line; content:"POST /cgi-bin/viewcert HTTP/1.1"; fast_pattern; http.request_body; content:"cert|3d|"; nocase; pcre:"/^[^\x0d\x0a\x26\x5c]*?\x5cn/R"; reference:cve,2021-20039; classtype:attempted-admin; sid:2034986; rev:3; metadata:attack_target Server, created_at 2022_01_26, cve CVE_2021_20039, deployment Perimeter, deployment Internal, confidence Medium, signature_severity Major, tag Exploit, updated_at 2025_04_14, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;)