alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT Microsoft Exchange RCE Setup Inbound (CVE-2021-28482)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/ews/Exchange.asmx"; http.request_body; content:"ProposeOptionsMeeting"; content:"&quot|3b|&gt|3b|cmd"; distance:0; fast_pattern; content:"Value&gt|3b|"; distance:0; reference:cve,2021-28482; classtype:attempted-admin; sid:2032897; rev:1; metadata:affected_product Microsoft_Exchange, attack_target Server, created_at 2021_05_04, cve CVE_2021_28482, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_12_23;)