alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET HUNTING Cisco IOS XE Web Server Auth From Suspicious Username (cisco_tac_admin) (CVE-2023-20198) (Outbound)";
flow:established,to_server;
http.method;
content:"GET";
http.cookie;
content:"Auth=cisco_tac_admin"; startswith; fast_pattern;
reference:url,blog.talosintelligence.com/active-exploitation-of-cisco-ios-xe-software/;
reference:cve,2023-20198;
classtype:misc-activity;
sid:2048939; rev:1;
metadata:attack_target Client_Endpoint, created_at 2023_10_30, cve CVE_2023_20198, deployment Perimeter, deployment SSLDecrypt, confidence Medium, signature_severity Informational, tag CISA_KEV, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_10_30, reviewed_at 2023_10_30;
)