ET WEB_SPECIFIC_APPS ServiceNow BodySnatcher Virtual Agent API Authentication Bypass (CVE-2025-12420)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS ServiceNow BodySnatcher Virtual Agent API Authentication Bypass (CVE-2025-12420)";
    flow:established,to_server;
    http.uri;
    content:"/api/sn_va_as_service/"; fast_pattern;
    http.header;
    content:"|0d 0a|token|3a 20|"; nocase;
    content:"x-usertoken|3a 20|"; nocase;
    http.request_body;
    content:"|22|appInboundId|22 3a 20 22|default-external-agent|22|";
    http.method;
    content:"POST";
    reference:url,appomni.com/ao-labs/bodysnatcher-agentic-ai-security-vulnerability-in-servicenow/;
    reference:cve,2025-12420;
    classtype:web-application-attack;
    sid:2067121; rev:1;
    metadata:affected_product ServiceNow, attack_target Server, tls_state TLSDecrypt, created_at 2026_01_27, cve CVE_2025_12420, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2026_01_27, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)