alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Roundcube rcube_washtml.php SVG Cross-Site Scripting (CVE-2023-5631)"; flow:established,to_client; http.response_body; content:"|3c|svg|3e 3c|use|20|href|3d 22|data:image/s"; fast_pattern; nocase; content:"vg+xml|3b|base64|2c|"; distance:0; base64_decode:bytes 200, offset 0, relative; base64_data; pcre:"/.+(script|onerror|onmouse[a-z]+|onkey[a-z]+|onload|onunload|ondragdrop|onblur|onfocus|onclick|ondblclick|onsubmit|onreset|onselect|onchange|style\x3D)/i"; reference:url,www.welivesecurity.com/en/eset-research/winter-vivern-exploits-zero-day-vulnerability-roundcube-webmail-servers/; reference:cve,2023-5631; classtype:web-application-attack; sid:2059117; rev:1; metadata:affected_product Roundcube, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_01_10, cve CVE_2023_5631, deployment Perimeter, deployment Internal, deployment Datacenter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag CISA_KEV, updated_at 2025_01_10, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)