alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Tenda GstDhcpSetSer dips Parameter Buffer Overflow Attempt (CVE-2026-3399)"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:21; content:"/goform/GstDhcpSetSer"; fast_pattern; http.request_body; content:"dips|3d|"; pcre:"/^[^&]{100,}(?:&|$)/R"; reference:url,github.com/advisories/GHSA-qgr9-jc5r-hw74; reference:cve,2026-3399; classtype:web-application-attack; sid:2069687; rev:1; metadata:affected_product Tenda, attack_target Networking_Equipment, tls_state plaintext, created_at 2026_06_09, cve CVE_2026_3399, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, updated_at 2026_06_09, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)