ET WEB_SERVER SonicWall SMA Unauthenticated sonicfiles Confused Deputy (CVE-2021-20042)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SERVER SonicWall SMA Unauthenticated sonicfiles Confused Deputy (CVE-2021-20042)";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/fileshare/sonicfiles/sonicfiles|3f|"; fast_pattern;
    content:"RacNumber|3d|25";
    content:"Arg1|3d|";
    pcre:"/^[a-z]+\x3a\x2f{2}/R";
    reference:url,www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/;
    reference:cve,2021-20042;
    classtype:web-application-attack;
    sid:2061554; rev:1;
    metadata:affected_product SonicWall, attack_target Server, tls_state TLSDecrypt, created_at 2025_04_14, cve CVE_2021_20042, deployment Perimeter, deployment Internal, deployment SSLDecrypt, signature_severity Major, tag Exploit, updated_at 2025_04_14, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)