ET WEB_SPECIFIC_APPS Hikvision Authentication Bypass Attempt M1 (user/password enumeration) (CVE-2017-7921)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS Hikvision Authentication Bypass Attempt M1 (user/password enumeration) (CVE-2017-7921)";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/Security/users|3f|auth|3d|YWRtaW4"; fast_pattern;
    reference:url,seclists.org/fulldisclosure/2017/Sep/23;
    reference:cve,2017-7921;
    classtype:attempted-admin;
    sid:2068369; rev:1;
    metadata:affected_product HikVision, attack_target Networking_Equipment, tls_state plaintext, created_at 2026_03_20, cve CVE_2017_7921, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, updated_at 2026_03_20, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)