alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS GitLab SAML Authentication Bypass (CVE-2025-25291)"; flow:established,to_server; http.uri; content:"/users/auth/saml/callback"; fast_pattern; http.request_body; content:"SAMLResponse|3d|"; base64_decode:offset 0,relative; base64_data; content:"|3c 21|DOCTYPE|20|"; content:"|3e 3c 21 2d 2d|"; distance:0; content:"|3c 21|ENTITY|20|"; distance:0; reference:url,portswigger.net/research/saml-roulette-the-hacker-always-wins; reference:cve,2025-25291; classtype:web-application-attack; sid:2065765; rev:1; metadata:affected_product Gitlab, attack_target Server, tls_state TLSDecrypt, created_at 2025_11_13, cve CVE_2025_25291, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_11_13, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)