alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT ManageEngine AdSelfService Plus - .jsp WebShell Upload Attempt (CVE-2021-40539)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/RestAPI/"; http.request_body; content:"form-data|3b 20|name=|22|methodToCall|22|"; fast_pattern; content:"unspecified"; within:30; content:"|20|name=|22|Save|22|"; content:"filename=|22|"; pcre:"/^[^\x22]+\.jsp\x22/R"; reference:url,www.synacktiv.com/publications/how-to-exploit-cve-2021-40539-on-manageengine-adselfservice-plus.html; reference:cve,2021-40539; classtype:attempted-admin; sid:2034364; rev:2; metadata:attack_target Server, created_at 2021_11_09, cve CVE_2021_40539, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, tag CISA_KEV, updated_at 2024_03_08, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;)