alert http any any -> $HOME_NET any (msg:"ET EXPLOIT Sophos Web Appliance Pre-Auth Command Injection Attempt (CVE-2023-1671)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/index.php?"; content:"c|3d|blocked"; http.request_body; content:"args_reason|3d|filetypewarn"; fast_pattern; content:"user_encoded|3d|"; pcre:"/^[^&]*?(?:[\x3b\x24\x26\x60\x7c]|\x25(?:25)*(?:3[bB]|2[46]|60|7[cC])|\x5c[rn])/R"; reference:url,sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce; classtype:attempted-admin; sid:2049632; rev:3; metadata:attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2023_12_11, cve CVE_2023_1671, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Major, tag cve_2023_1671, tag CISA_KEV, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_10_21, mitre_tactic_id TA0008, mitre_tactic_name Lateral_Movement, mitre_technique_id T1210, mitre_technique_name Exploitation_Of_Remote_Services; target:dest_ip;)