ET EXPLOIT Possible Microsoft Exchange RCE Inbound M2 (CVE-2021-34473)

Query · suricata

flow:established,to_server;
http.method;
content:"POST";
http.uri;
content:"/autodiscover.json?";
content:"/PowerShell/"; nocase; distance:0;
content:"X-Rps-CAT="; distance:0; fast_pattern;
content:"Email="; distance:0;
content:"autodiscover/"; distance:0; within:20;
Raw source ET EXPLOIT Possible Microsoft Exchange RCE Inbound M2 (CVE-2021-34473) · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (
    msg:"ET EXPLOIT Possible Microsoft Exchange RCE Inbound M2 (CVE-2021-34473)";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/autodiscover.json?";
    content:"/PowerShell/"; nocase; distance:0;
    content:"X-Rps-CAT="; distance:0; fast_pattern;
    content:"Email="; distance:0;
    content:"autodiscover/"; distance:0; within:20;
    reference:cve,2021-34473;
    classtype:attempted-admin;
    sid:2033711; rev:2;
    metadata:affected_product Microsoft_Exchange, attack_target Server, created_at 2021_08_12, 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;
)

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