alert http $EXTERNAL_NET any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT Cisco IOS XE Web Server Possible Authentication Bypass Attempt (CVE-2023-20198) (Inbound)"; flow:established,to_server; http.method; content:"POST"; http.uri.raw; content:"|25|25"; http.request_body; content:"|3c|SOAP|3a|Body|3e|"; nocase; content:"|3c|request correlator|3d 22|"; nocase; distance:0; 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:attempted-admin; sid:2048941; rev:3; metadata:created_at 2023_10_30, cve CVE_2023_20198, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag CISA_KEV, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_10_31, reviewed_at 2024_01_26, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)