Name:Kubernetes Nginx Ingress RFI id:fc5531ae-62fd-4de6-9c36-b4afdae8ca95 version:5 date:2024-09-30 author:Patrick Bareiss, Splunk status:production type:TTP Description:The following analytic detects remote file inclusion (RFI) attacks targeting Kubernetes Nginx ingress controllers. It leverages Kubernetes logs from the Nginx ingress controller, parsing fields such as `remote_addr`, `request`, and `url` to identify suspicious activity. This activity is significant because RFI attacks can allow attackers to execute arbitrary code or access sensitive files on the server. If confirmed malicious, this could lead to unauthorized access, data exfiltration, or further compromise of the Kubernetes environment. Data_source:
search:`kubernetes_container_controller` | rex field=_raw "^(?<remote_addr>\S+)\s+-\s+-\s+\[(?<time_local>[^\]]*)\]\s\"(?<request>[^\"]*)\"\s(?<status>\S*)\s(?<body_bytes_sent>\S*)\s\"(?<http_referer>[^\"]*)\"\s\"(?<http_user_agent>[^\"]*)\"\s(?<request_length>\S*)\s(?<request_time>\S*)\s\[(?<proxy_upstream_name>[^\]]*)\]\s\[(?<proxy_alternative_upstream_name>[^\]]*)\]\s(?<upstream_addr>\S*)\s(?<upstream_response_length>\S*)\s(?<upstream_response_time>\S*)\s(?<upstream_status>\S*)\s(?<req_id>\S*)" | rex field=request "^(?<http_method>\S+)?\s(?<url>\S+)\s" | rex field=url "(?<dest_ip>\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})" | search dest_ip=* | rename remote_addr AS src_ip, upstream_status as status, proxy_upstream_name as proxy | eval phase="operate" | eval severity="medium" | stats count min(_time) as firstTime max(_time) as lastTime by src_ip, dest_ip status, url, http_method, host, http_user_agent, proxy, phase, severity | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `kubernetes_nginx_ingress_rfi_filter`
how_to_implement:You must ingest Kubernetes logs through Splunk Connect for Kubernetes. known_false_positives:unknown References: -https://github.com/splunk/splunk-connect-for-kubernetes -https://www.invicti.com/blog/web-security/remote-file-inclusion-vulnerability/ drilldown_searches: name:'View the detection results for - "$host$"' search:'%original_detection_search% | search host = "$host$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$host$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$host$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Dev Sec Ops' asset_type:Kubernetes confidence:70 impact:70 message:Remote File Inclusion Attack detected on $host$ mitre_attack_id: - 'T1212' observable: name:'host' type:'Hostname' - role: - 'Victim' name:'src_ip' type:'IP Address' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - 'raw' risk_score:49 security_domain:network
