ET WEB_SERVER SonicWall SMA Unauthenticated handleWAFRedirect CGI Arbitrary File Deletion (CVE-2021-20034)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SERVER SonicWall SMA Unauthenticated handleWAFRedirect CGI Arbitrary File Deletion (CVE-2021-20034)";
    flow:established,to_server;
    http.uri;
    content:"/cgi-bin/handleWAFRedirect|3f|"; fast_pattern;
    content:"hdl|3d|";
    pcre:"/^[^&]*?(?:(?:\x2e|%2[Ee]){1,2}(?:\x2f|\x5c|%5[Cc]|%2[Ff]){1,}){2,}/R";
    reference:url,attackerkb.com/topics/23t9VCbGzt/cve-2021-20034/rapid7-analysis;
    reference:cve,2021-20034;
    classtype:web-application-attack;
    sid:2061721; rev:1;
    metadata:affected_product SonicWall, attack_target Server, tls_state TLSDecrypt, created_at 2025_04_17, cve CVE_2021_20034, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2025_04_17, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)