Kubernetes Ingress Created Without TLS

Severity: medium
Group by: name, namespace
Log types: Amazon.EKS.Audit, Azure.MonitorActivity, GCP.AuditLog
Tags: Kubernetes, Network Security, Encryption, Compliance, Unified Detection
Reference: https://kubernetes.io/docs/concepts/services-networking/ingress/#tls
Source: github.com/panther-labs/panther-analysis

This detection monitors for Ingress objects being created without TLS certificates configured. Ingresses without TLS expose services over unencrypted HTTP, allowing sensitive data like passwords, tokens, and PII to be transmitted in cleartext. This violates security best practices and compliance requirements like PCI-DSS and HIPAA, and enables man-in-the-middle attacks.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1040` Network Sniffing, `T1552.004` Unsecured Credentials: Private Keys

Rule body yaml

AnalysisType: rule
RuleID: "Kubernetes.Ingress.NoTLS"
DisplayName: "Kubernetes Ingress Created Without TLS"
Enabled: true
Filename: k8s_ingress_without_tls.py
LogTypes:
  - Amazon.EKS.Audit
  - Azure.MonitorActivity
  - GCP.AuditLog
Tags:
  - Kubernetes
  - Network Security
  - Encryption
  - Compliance
  - Unified Detection
Severity: Medium
Description: >
  This detection monitors for Ingress objects being created without TLS certificates configured. Ingresses
  without TLS expose services over unencrypted HTTP, allowing sensitive data like passwords, tokens, and PII
  to be transmitted in cleartext. This violates security best practices and compliance requirements like
  PCI-DSS and HIPAA, and enables man-in-the-middle attacks.
Runbook: |
  1. Review the ingress specification to determine if this is an internal-only service or if TLS is terminated at an external load balancer
  2. If TLS is required, work with the team to configure TLS certificates using cert-manager or manual certificate creation
  3. Search for other ingresses without TLS in the past 7 days to identify if this is a systemic configuration issue
Reports:
  MITRE ATT&CK:
    - TA0009:T1040 # Collection: Network Sniffing
    - TA0006:T1552.004 # Credential Access: Unsecured Credentials - Private Keys
Reference: https://kubernetes.io/docs/concepts/services-networking/ingress/#tls
DedupPeriodMinutes: 60
SummaryAttributes:
  - username
  - namespace
  - name
  - p_source_label
Tests:
  - Name: EKS Ingress without TLS
    ExpectedResult: true
    Log:
      {
        "kind": "Event",
        "apiVersion": "audit.k8s.io/v1",
        "verb": "create",
        "user": {"username": "developer@example.com"},
        "sourceIPs": ["203.0.113.42"],
        "userAgent": "kubectl/v1.28.0",
        "objectRef": {
          "resource": "ingresses",
          "namespace": "production",
          "name": "api-ingress",
          "apiGroup": "networking.k8s.io",
          "apiVersion": "v1"
        },
        "responseStatus": {"code": 201},
        "requestObject": {
          "kind": "Ingress",
          "metadata": {
            "name": "api-ingress",
            "namespace": "production",
            "annotations": {
              "kubernetes.io/ingress.class": "nginx"
            }
          },
          "spec": {
            "rules": [
              {
                "host": "api.example.com",
                "http": {
                  "paths": [
                    {
                      "path": "/",
                      "backend": {
                        "serviceName": "api-service",
                        "servicePort": 80
                      }
                    }
                  ]
                }
              }
            ]
          }
        },
        "p_log_type": "Amazon.EKS.Audit",
        "p_source_label": "eks-cluster"
      }
  - Name: AKS Ingress without TLS
    ExpectedResult: true
    Log:
      {
        "p_log_type": "Azure.MonitorActivity",
        "category": "kube-audit",
        "operationName": "Microsoft.ContainerService/managedClusters/diagnosticLogs/Read",
        "properties": {
          "log": "{\"kind\":\"Event\",\"apiVersion\":\"audit.k8s.io/v1\",\"verb\":\"create\",\"user\":{\"username\":\"admin@example.com\"},\"sourceIPs\":[\"1.2.3.4\"],\"objectRef\":{\"resource\":\"ingresses\",\"namespace\":\"default\",\"name\":\"test-ingress\",\"apiGroup\":\"networking.k8s.io\"},\"responseStatus\":{\"code\":201},\"requestObject\":{\"kind\":\"Ingress\",\"metadata\":{\"name\":\"test-ingress\"},\"spec\":{\"rules\":[{\"http\":{\"paths\":[{\"path\":\"/testpath\",\"backend\":{\"serviceName\":\"test\",\"servicePort\":80}}]}}]}}}"
        },
        "p_source_label": "aks-cluster"
      }
  - Name: GKE Ingress without TLS with external DNS annotation
    ExpectedResult: true
    Log:
      {
        "protoPayload": {
          "authenticationInfo": {"principalEmail": "user@company.com"},
          "authorizationInfo": [{
            "granted": true,
            "permission": "io.k8s.networking.v1.ingresses.create",
            "resource": "networking.k8s.io/v1/namespaces/production/ingresses/web-ingress"
          }],
          "methodName": "io.k8s.networking.v1.ingresses.create",
          "requestMetadata": {"callerIP": "8.8.8.8"},
          "resourceName": "networking.k8s.io/v1/namespaces/production/ingresses/web-ingress",
          "serviceName": "k8s.io",
          "request": {
            "kind": "Ingress",
            "metadata": {
              "name": "web-ingress",
              "annotations": {
                "external-dns.alpha.kubernetes.io/hostname": "web.example.com"
              }
            },
            "spec": {
              "rules": [
                {
                  "host": "web.example.com",
                  "http": {
                    "paths": [{"path": "/", "backend": {"serviceName": "web", "servicePort": 8080}}]
                  }
                }
              ]
            }
          }
        },
        "resource": {
          "type": "k8s_cluster",
          "labels": {"project_id": "test-project"}
        },
        "p_log_type": "GCP.AuditLog",
        "p_source_label": "gke-cluster"
      }
  - Name: EKS Ingress with TLS configured
    ExpectedResult: false
    Log:
      {
        "kind": "Event",
        "verb": "create",
        "user": {"username": "developer@example.com"},
        "objectRef": {
          "resource": "ingresses",
          "namespace": "production",
          "name": "secure-ingress"
        },
        "responseStatus": {"code": 201},
        "requestObject": {
          "kind": "Ingress",
          "spec": {
            "tls": [
              {
                "hosts": ["api.example.com"],
                "secretName": "api-tls-cert"
              }
            ],
            "rules": [
              {
                "host": "api.example.com",
                "http": {"paths": [{"path": "/", "backend": {"serviceName": "api", "servicePort": 443}}]}
              }
            ]
          }
        },
        "p_log_type": "Amazon.EKS.Audit"
      }
  - Name: System namespace (excluded)
    ExpectedResult: false
    Log:
      {
        "kind": "Event",
        "verb": "create",
        "user": {"username": "admin@example.com"},
        "objectRef": {
          "resource": "ingresses",
          "namespace": "kube-system",
          "name": "system-ingress"
        },
        "responseStatus": {"code": 201},
        "requestObject": {
          "kind": "Ingress",
          "spec": {
            "rules": [{"http": {"paths": [{"path": "/"}]}}]
          }
        },
        "p_log_type": "Amazon.EKS.Audit"
      }
  - Name: Failed request (excluded)
    ExpectedResult: false
    Log:
      {
        "kind": "Event",
        "verb": "create",
        "user": {"username": "developer@example.com"},
        "objectRef": {
          "resource": "ingresses",
          "namespace": "production",
          "name": "test-ingress"
        },
        "responseStatus": {"code": 403},
        "requestObject": {
          "kind": "Ingress",
          "spec": {
            "rules": [{"http": {"paths": [{"path": "/"}]}}]
          }
        },
        "p_log_type": "Amazon.EKS.Audit"
      }
  - Name: Updating existing ingress (not creating)
    ExpectedResult: false
    Log:
      {
        "kind": "Event",
        "verb": "update",
        "user": {"username": "admin@example.com"},
        "objectRef": {
          "resource": "ingresses",
          "namespace": "production",
          "name": "api-ingress"
        },
        "responseStatus": {"code": 200},
        "requestObject": {
          "kind": "Ingress",
          "spec": {
            "rules": [{"http": {"paths": [{"path": "/"}]}}]
          }
        },
        "p_log_type": "Amazon.EKS.Audit"
      }

Detection logic

Condition

not (verb ne "create" or resource ne "ingresses")
not (responseStatus is_not_null and (responseStatus.code ge "400" or (responseStatus.code ge "1" and responseStatus.code le "16")))
not ((namespace is_not_null and namespace in ["kube-system", "gke-system", "kube-node-lease", "kube-public"]) or (username is_not_null and (username in ["masterclient", "aksService"] or (username starts_with "system:" and username not contains "serviceaccount"))))
requestObject.spec.tls is_null

This rule also runs imperative logic the parser cannot express as a filter; the conditions above are the structured part it could extract.

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`username`	contains	`serviceaccount`
`username`	starts_with	`system:`
`username`	in	`aksService`, `masterclient`
`username`	is_not_null	(no value, null check)
`namespace`	in	`gke-system`, `kube-node-lease`, `kube-public`, `kube-system`
`namespace`	is_not_null	(no value, null check)
`responseStatus.code`	ge	`1`
`responseStatus.code`	le	`16`
`responseStatus.code`	ge	`400`
`responseStatus`	is_not_null	(no value, null check)
`resource`	ne	`ingresses`
`verb`	ne	`create`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`requestObject.spec.tls`	is_null	(no value, null check)
`username`	contains	`serviceaccount`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`username`
`sourceIPs`
`userAgent`
`namespace`
`verb`
`resource`
`requestURI`
`responseStatus`
`cluster`	`p_source_label`
`name`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)