alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT SonicWall SMA Stack-Based Buffer Overflow CVE-2021-20038 M1"; flow:established,to_server; urilen:>400; threshold:type threshold, track by_src, count 10, seconds 30; http.request_line; content:"GET /%"; startswith; pcre:"/^[a-zA-Z0-9]{2}[%a-zA-Z0-9]{9}(?P<addr>(?:[%a-zA-Z0-9]{3}){4})(?P=addr)/R"; content:"%64%b8%06%08"; within:55; fast_pattern; content:"?"; reference:cve,2021-20038; classtype:attempted-admin; sid:2034984; rev:2; metadata:attack_target Server, created_at 2022_01_26, cve CVE_2021_20038, 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;)