alert http any any -> [$HTTP_SERVERS,$HOME_NET] any (msg:"ET EXPLOIT Zyxel NWA-1100-NH Command Injection Attempt (CVE-2021-4039)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/login/login.html"; bsize:17; fast_pattern; http.request_body; content:"myname="; content:"mypasswd="; content:"Submit=Login"; pcre:"/myname=[^&]+(?:[\x60\x3b\x7c\x26]|%60|%3b|%7c|%26|(?:[\x3c\x3e\x24]|%3c|%3e|%24)(?:\x28|%28))/i"; reference:url,www.zyxel.com/support/OS-command-injection-vulnerability-of-NWA1100-NH-access-point.shtml; reference:url,cybersecurity.att.com/blogs/labs-research/rapidly-evolving-iot-malware-enemybot-now-targeting-content-management-system-servers; reference:url,www.exploit-db.com/exploits/50870; reference:cve,2021-4039; classtype:attempted-admin; sid:2036737; rev:1; metadata:attack_target Networking_Equipment, created_at 2022_06_01, cve CVE_2021_4039, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_06_01, mitre_tactic_id TA0008, mitre_tactic_name Lateral_Movement, mitre_technique_id T1210, mitre_technique_name Exploitation_Of_Remote_Services;)