alert http $EXTERNAL_NET any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET HUNTING Suspicious Cisco Privilege Level 15 in HTTP Header (Inbound)"; flow:established,to_server; http.request_header; header_lowercase; bsize:14; content:"priv-level|3a 20|15"; fast_pattern; startswith; threshold:type limit,seconds 300,count 1,track by_src; reference:url,blog.talosintelligence.com/active-exploitation-of-cisco-ios-xe-software/; reference:url,twitter.com/SI_FalconTeam/status/1718346358950711807; reference:cve,2023-20198; classtype:misc-activity; sid:2048936; rev:2; metadata:attack_target Networking_Equipment, created_at 2023_10_30, cve CVE_2023_20198, deployment Perimeter, deployment SSLDecrypt, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_27, reviewed_at 2023_10_30;)