alert http $EXTERNAL_NET any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT Cisco IOS XE Web Server Implant Check (CVE-2023-20198) M3"; flow:established,to_server; urilen:32; http.method; content:"POST"; http.uri; content:"|2f|webui|2f|logoutconfirm|2e|html|3f|menu|3d|1"; fast_pattern; threshold:type limit,seconds 300,count 1,track by_src; reference:url,blog.talosintelligence.com/active-exploitation-of-cisco-ios-xe-software/; reference:cve,2023-20198; classtype:trojan-activity; sid:2049103; rev:1; metadata:attack_target Networking_Equipment, created_at 2023_11_07, cve CVE_2023_20198, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Major, tag CISA_KEV, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_11_07;)