alert http any any -> $HOME_NET any (msg:"ET HUNTING Microsoft Sharepoint Deserialization RCE via Workflow (CVE-2018-8421)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/_vti_bin/webpartpages.asmx"; http.request_body; content:"|3c|ValidateWorkflowMarkupAndCreateSupportObjects"; fast_pattern; content:"|3c|workflowMarkupText|3e|"; content:"|3c 21 5b|CDATA|5b|"; distance:0; reference:url,www.nccgroup.com/research-blog/technical-advisory-bypassing-microsoft-xoml-workflows-protection-mechanisms-using-deserialisation-of-untrusted-data/; reference:cve,2018-8421; classtype:web-application-attack; sid:2064136; rev:1; metadata:affected_product Microsoft_Sharepoint, attack_target Server, tls_state TLSDecrypt, created_at 2025_08_25, cve CVE_2018_8421, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_25, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)