alert http any any -> [$HOME_NET,$HTTP_SERVERS] [443,444] (
msg:"ET EXPLOIT Possible Microsoft Exchange RCE Inbound M1 (CVE-2021-34473)";
flow:established,to_server;
http.method;
content:"POST";
http.uri;
content:"/ews/exchange.asmx"; fast_pattern;
http.request_body;
content:"<s";
content:"SerializedSecurityContext>"; distance:0;
content:"Message>"; distance:0;
content:"Attachments>"; distance:0;
content:"Content>"; distance:0;
content:"|60 c2 ac c2 aa|"; distance:0; within:200;
reference:cve,2021-34473;
classtype:attempted-admin;
sid:2033684; rev:3;
metadata:affected_product Microsoft_Exchange, attack_target Server, created_at 2021_08_09, cve CVE_2021_34473, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence Medium, signature_severity Major, tag Exploit, tag CISA_KEV, updated_at 2022_12_23, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
)