ET WEB_SPECIFIC_APPS Atlassian Confluence Server-Side Request Forgery (CVE-2021-26072)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS Atlassian Confluence Server-Side Request Forgery (CVE-2021-26072)";
    flow:established,to_server;
    http.uri;
    content:"/rest/sharelinks/1.0/link|3f|"; fast_pattern;
    content:"url|3d|";
    pcre:"/^[a-z]+(?:\x3a|\x253[aA])(?:\x2f{2}|(?:\x252[fF]){2})/R";
    reference:url,github.com/assetnote/blind-ssrf-chains#confluence;
    reference:cve,2021-26072;
    classtype:web-application-attack;
    sid:2065569; rev:1;
    metadata:affected_product Atlassian_Confluence, attack_target Server, tls_state TLSDecrypt, created_at 2025_10_30, cve CVE_2021_26072, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_10_30, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)