ET WEB_SPECIFIC_APPS [Perch Security] Nagios XI Web SSH Terminal sshterm Cross-Site Scripting (CVE-2021-25299)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS [Perch Security] Nagios XI Web SSH Terminal sshterm Cross-Site Scripting (CVE-2021-25299)";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/nagiosxi/admin/sshterm.php?"; startswith; fast_pattern;
    content:"url="; nocase;
    pcre:"/^.+(script|onerror|onmouse[a-z]+|onkey[a-z]+|onload|onunload|ondragdrop|onblur|onfocus|onclick|ondblclick|onsubmit|onreset|onselect|onchange|style\x3D)/Ri";
    reference:url,www.connectwise.com/resources/cve-spotlight-nagios-xi-cve-2021-25296-25297-25298-25299;
    reference:cve,2021-25299;
    classtype:web-application-attack;
    sid:2059094; rev:2;
    metadata:affected_product Nagios, attack_target Web_Server, tls_state plaintext, created_at 2025_01_09, cve CVE_2021_25299, deployment Perimeter, deployment Internal, deployment Datacenter, performance_impact Low, confidence High, signature_severity Major, tag Exploit, 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;
)