漏洞扫描 –编写Nmap NSE脚本

漏洞扫描 —编写Nmap脚本

200612月份,Nmap4.21 ALPHA1版加入脚本引擎,并将其作为主线代码的一部分。NSE脚本库如今已经有400多个脚本,覆盖了各种不同的网络机制(SMB漏洞检测到Stuxnet探测,及中间的一些内容)NSE的强大,依赖它强大的功能库,这些库可以非常容易的与主流的网络服务和协议,进行交互。

挑战

我们经常会扫描网络环境中的主机是否存在某种新漏洞,而扫描器引擎中没有新漏洞的检测方法,这时候我们可能需要自己开发扫描工具。

你可能已经熟悉了某种脚本(例如:PythonPerltc.),并可以快速写出检测漏洞的程序。但是,如果面临许多主机时,
针对两三个主机的检测方法,可能并不奏效。

Nmap 解救你 !使用内嵌的Lua语言和强大的集合库,你可以结合nmap高效的主机和端口扫描引擎,开发出针对多数主机的检测方法。

实现

Nmap 引擎脚本,由Lua编程语言、NmapAPI、系列强大的NSE库实现。为了达到本文的目的,现假设某个应用中存在一个叫ArcticFission漏洞。与许多其他的web应用程序类似,可以通过探测特定的文件,假设这个文件就是arcticfission.html,用正则表达式提取文件内容中的版本号,与有漏洞的值进行对比.听起来好像很简单,让我们开始吧
!

框架代码

基于传统的语言标准,我们写一个脚本,作用:遇到开放的HTTP端口,就返回”Hello World”

-- The Head Section --  
-- The Rule Section --  
portrule = function(host, port)  
    return port.protocol == "tcp" and port.number == 80 and port.state == "open"  
end  
 
-- The Action Section --  
action = function(host, port)  
    return "Hello world !"  
end  

注意:起始的行表示注释。

NSE脚本主要由三部分组成:

The Head Section

该部分包含一些元数据,主要描述脚本的功能,作者,影响力,类别及其他。

The Rule Section

该部分定义脚本执行的必要条件。至少包含下面列表中的一个函数:
portrule
hostrule
prerule
postrule

此案例中,重点介绍portruleportrule能够在执行操作前,检查hostport属性。portrule会利用nmapAPI检查TCP80端口。

The Action Section

该部分定义脚本逻辑。此处案例中,检测到开放80端口,则打印“HelloWorld”。脚本的输出内容,会在nmap执行期间显示出来。

root@security:~$ nmap -sS -p 22,80,443 --script /home/offensive/nmap_nse/http-vuln-check.nse www.exploit-db.com 
 
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-29 10:39 EDT  
Nmap scan report for www.exploit-db.com (192.99.12.218)  
Host is up (0.47s latency).  
Other addresses for www.exploit-db.com (not scanned): 198.58.102.135  
rDNS record for 192.99.12.218: cloudproxy71.sucuri.net  
PORT    STATE    SERVICE  
22/tcp  filtered ssh  
80/tcp  open     http  
|_http-vuln-check: Hello world !  
443/tcp open     https 

调用脚本库

优秀的库集合,促使其变的强大。例如,可调用现有库中的函数,针对http端口创建portrule。此处用到了shortport.

local shortport = require "shortport"  
 
-- The Rule Section --  
portrule = shortport.http  
 
-- The Action Section --  
action = function(host, port)  
    return "Hello world!"  
end 

同样的扫描,产生了不同的结果

root@security:~$ nmap -sS -p 22,80,443 --script /home/offensive/nmap_nse/http-vuln-check_shortport.nse www.exploit-db.com 
 
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-29 10:36 EDT  
Nmap scan report for www.exploit-db.com (192.99.12.218)  
Host is up (0.46s latency).  
Other addresses for www.exploit-db.com (not scanned): 198.58.102.135  
rDNS record for 192.99.12.218: cloudproxy71.sucuri.net  
PORT    STATE    SERVICE  
22/tcp  filtered ssh  
80/tcp  open     http  
|_http-vuln-check_shortport: Hello world!  
443/tcp open     https  
|_http-vuln-check_shortport: Hello world!  
 
Nmap done: 1 IP address (1 host up) scanned in 6.32 seconds 

该脚本对443执行了类似80端口的操作。主要是因为shortport.http表示类似HTTP的端口(80,443,631,7080,8080,8088,5800,3872,8180,8000),也就是说,nmap会探测服务httphttpsipphttp-altvnc-httpm-agentsoaphttp-proxy非标准端口,如果想要获取更多的信息,请查阅shortport的文档.

服务探测

让我们把注意力放到action
部分的逻辑上。上述漏洞的检测,首先需要探测页面”arcticfission.html”

local shortport = require "shortport"  
local http = require "http"  
 
-- The Rule Section --  
portrule = shortport.http  
 
-- The Action Section --  
action = function(host, port)  
    local uri = "/arcticfission.html"  
    local response = http.get(host, port, uri)  
    return response.status  
end 

上述代码用到了库http处理web页面,

root@security:~$ nmap -sS -p 22,80,443 --script /home/offensive/nmap_nse/http-vuln-check_shortport2.nse www.exploit-db.com 
 
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-29 11:16 EDT  
Nmap scan report for www.exploit-db.com (192.99.12.218)  
Host is up (0.48s latency).  
Other addresses for www.exploit-db.com (not scanned): 198.58.102.135  
rDNS record for 192.99.12.218: cloudproxy71.sucuri.net  
PORT    STATE    SERVICE  
22/tcp  filtered ssh  
80/tcp  open     http  
|_http-vuln-check_shortport2: 403  
443/tcp open     https  
|_http-vuln-check_shortport2: 400 

上述输出表明,两个服务器端口不存在对应页面”arcticfission.html”,注意‘http’库会自动在httphttps端口切换,因此你不需要考虑去实现TLS/SSL

如果只想输出存在该页面的web应用,可以如下操作:

local shortport = require "shortport"  
local http = require "http"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
  
    local uri = "/arcticfission.html"  
    local response = http.get(host, port, uri)  
  
    if (response.status == 200) then  
        return response.body  
    end  
end 

上述代码,返回状态码为200的页面内容。

注意:如果没有数据返回或返回数据为空,将导致无输出显示.

漏洞探测

许多时候,可以通过一个简单的服务版本号,探测漏洞。这种情况,假象的服务器会返回一个包含版本号的标识。

local shortport = require "shortport"  
local http = require "http"  
local string = require "string"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
  
    local uri = "/arcticfission.html"  
    local response = http.get(host, port, uri)  
  
    if ( response.status == 200 ) then  
        local title = string.match(response.body, "<[Tt][Ii][Tt][Ll][Ee][^>]*>ArcticFission ([^<]*)</[Tt][Ii][Tt][Ll][Ee]>") 
        return title  
    end  
end

上述代码,用到了string库,以便获取页面头。

offensive@security:~$ nmap -p 80,443 --script /home/offensive/nmap_nse/http-vuln-check_shortport4.nse 192.168.1.105 
  
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-30 03:49 EDT  
Nmap scan report for localhost (192.168.1.105)  
Host is up (0.00053s latency).  
PORT    STATE  SERVICE  
80/tcp  open   http  
|_http-vuln-check_shortport4: 1.0  
443/tcp closed https  
  
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds 

正如上面描述的那样,现在需要将获取的值与漏洞值比较, 确认是否存在漏洞。

local shortport = require "shortport"  
local http = require "http"  
local string = require "string"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
  
    local uri = "/arcticfission.html"  
    local response = http.get(host, port, uri)  
  
    if ( response.status == 200 ) then  
        local title = string.match(response.body, "<[Tt][Ii][Tt][Ll][Ee][^>]*>ArcticFission ([^<]*)</[Tt][Ii][Tt][Ll][Ee]>") 
  
        if ( title == "1.0" ) then  
            return "Vnlnerable"  
        else  
            return "Not Vulnerable"  
        end  
    end  
end 

测试结果如下:

offensive@security:~$ nmap -p 80,443 --script /home/offensive/nmap_nse/http-vuln-check_shortport5.nse 192.168.1.105 
  
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-30 04:05 EDT  
Nmap scan report for localhost (192.168.1.105)  
Host is up (0.00045s latency).  
PORT    STATE  SERVICE  
80/tcp  open   http  
|_http-vuln-check_shortport5: Vnlnerable  
443/tcp closed https 

版本检测的另一种方法,生成Hash与有漏洞的页面对比。为了实现此效果,此处调用了openssl库。

local shortport = require "shortport"  
local http = require "http"  
local stdnse = require "stdnse"  
local openssl = require "openssl"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
  
    local uri = "/arcticfission.html"  
    local response = http.get(host, port, uri)  
  
    if (response.status == 200) then  
        local vulnsha1 = "398ffad678f17a4f16ccd00b1914ca986d0b9258"   
        local sha1 = string.lower(stdnse.tohex(openssl.sha1(response.body)))  
  
        if ( sha1 == vulnsha1 ) then  
            return "Vulnerable"  
        else  
            return "Not Vulnerable"  
        end  
    end  
end 

添加隐藏属性

使用第三方的库时,测试脚本的执行流程很重要。

offensive@security:~$ nmap -p 80,443 --script /home/offensive/nmap_nse/http-vuln-check_openssl.nse --script-trace 192.168.1.105 
  
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-30 05:38 EDT  
NSOCK INFO [0.0600s] nsi_new2(): nsi_new (IOD #1)  
NSOCK INFO [0.0610s] nsock_connect_tcp(): TCP connection requested to 192.168.1.105:80 (IOD #1) EID 8 
NSOCK INFO [0.0610s] nsock_trace_handler_callback(): Callback: CONNECT SUCCESS for EID 8 [192.168.1.105:80] 
NSE: TCP 192.168.1.106:59791 > 192.168.1.105:80 | CONNECT  
NSE: TCP 192.168.1.106:59791 > 192.168.1.105:80 | 00000000: 47 45 54 20 2f 61 72 63 74 69 63 66 69 73 73 69 GET /arcticfissi 
00000010: 6f 6e 2e 68 74 6d 6c 20 48 54 54 50 2f 31 2e 31 on.html HTTP/1.1  
00000020: 0d 0a 48 6f 73 74 3a 20 6c 6f 63 61 6c 68 6f 73   Host: localhos  
00000030: 74 0d 0a 43 6f 6e 6e 65 63 74 69 6f 6e 3a 20 63 t  Connection: c  
00000040: 6c 6f 73 65 0d 0a 55 73 65 72 2d 41 67 65 6e 74 lose  User-Agent  
00000050: 3a 20 4d 6f 7a 69 6c 6c 61 2f 35 2e 30 20 28 63 : Mozilla/5.0 (c  
00000060: 6f 6d 70 61 74 69 62 6c 65 3b 20 4e 6d 61 70 20 ompatible; Nmap   
00000070: 53 63 72 69 70 74 69 6e 67 20 45 6e 67 69 6e 65 Scripting Engine  
00000080: 3b 20 68 74 74 70 3a 2f 2f 6e 6d 61 70 2e 6f 72 ; http://nmap.or  
00000090: 67 2f 62 6f 6f 6b 2f 6e 73 65 2e 68 74 6d 6c 29 g/book/nse.html)  
000000a0: 0d 0a 0d 0a                                           
  
NSOCK INFO [0.0620s] nsock_trace_handler_callback(): Callback: WRITE SUCCESS for EID 19 [192.168.1.105:80] 
NSE: TCP 192.168.1.106:59791 > 192.168.1.105:80 | SEND  
NSOCK INFO [0.0620s] nsock_read(): Read request from IOD #1 [192.168.1.105:80] (timeout: 8000ms) EID 26 
NSOCK INFO [0.0640s] nsock_trace_handler_callback(): Callback: READ SUCCESS for EID 26 [192.168.1.105:80] (392 bytes) 
NSE: TCP 192.168.1.106:59791 < 192.168.1.105:80 | 00000000: 48 54 54 50 2f 31 2e 31 20 32 30 30 20 4f 4b 0d HTTP/1.1 200 OK   
00000010: 0a 44 61 74 65 3a 20 54 75 65 2c 20 33 30 20 53  Date: Tue, 30 S  
00000020: 65 70 20 32 30 31 34 20 30 39 3a 33 38 3a 34 39 ep 2014 09:38:49  
00000030: 20 47 4d 54 0d 0a 53 65 72 76 65 72 3a 20 41 70  GMT  Server: Ap  
00000040: 61 63 68 65 2f 32 2e 32 2e 32 32 20 28 44 65 62 ache/2.2.22 (Deb  
00000050: 69 61 6e 29 0d 0a 4c 61 73 74 2d 4d 6f 64 69 66 ian)  Last-Modif  
00000060: 69 65 64 3a 20 54 75 65 2c 20 33 30 20 53 65 70 ied: Tue, 30 Sep  
00000070: 20 32 30 31 34 20 30 37 3a 33 30 3a 33 33 20 47  2014 07:30:33 G  
00000080: 4d 54 0d 0a 45 54 61 67 3a 20 22 65 31 31 38 31 MT  ETag: "e1181  
00000090: 2d 37 34 2d 35 30 34 34 33 35 62 64 38 36 62 30 -74-504435bd86b0  
000000a0: 32 22 0d 0a 41 63 63 65 70 74 2d 52 61 6e 67 65 2"  Accept-Range  
000000b0: 73 3a 20 62 79 74 65 73 0d 0a 43 6f 6e 74 65 6e s: bytes  Conten  
000000c0: 74 2d 4c 65 6e 67 74 68 3a 20 31 31 36 0d 0a 56 t-Length: 116  V  
000000d0: 61 72 79 3a 20 41 63 63 65 70 74 2d 45 6e 63 6f ary: Accept-Enco  
000000e0: 64 69 6e 67 0d 0a 43 6f 6e 6e 65 63 74 69 6f 6e ding  Connection  
000000f0: 3a 20 63 6c 6f 73 65 0d 0a 43 6f 6e 74 65 6e 74 : close  Content  
00000100: 2d 54 79 70 65 3a 20 74 65 78 74 2f 68 74 6d 6c -Type: text/html  
00000110: 0d 0a 0d 0a 3c 68 74 6d 6c 3e 0a 3c 68 65 61 64     <html> <head  
00000120: 3e 0a 3c 74 69 74 6c 65 3e 41 72 63 74 69 63 46 > <title>ArcticF  
00000130: 69 73 73 69 6f 6e 20 31 2e 30 3c 2f 74 69 74 6c ission 1.0</titl  
00000140: 65 3e 0a 3c 2f 68 65 61 64 3e 0a 3c 62 6f 64 79 e> </head> <body  
00000150: 3e 0a 3c 68 31 3e 57 65 6c 63 6f 6d 65 20 74 6f > <h1>Welcome to  
00000160: 20 41 72 63 74 69 63 46 69 73 73 69 6f 6e 20 31  ArcticFission 1  
00000170: 2e 30 3c 2f 68 31 3e 0a 3c 2f 62 6f 64 79 3e 0a .0</h1> </body>   
00000180: 3c 2f 68 74 6d 6c 3e 0a                         </html>   
  
NSE: TCP 192.168.1.106:59791 > 192.168.1.105:80 | CLOSE  
NSOCK INFO [0.0640s] nsi_delete(): nsi_delete (IOD #1)  
Nmap scan report for localhost (192.168.1.105)  
Host is up (0.00064s latency).  
PORT    STATE  SERVICE  
80/tcp  open   http  
|_http-vuln-check_openssl: Vulnerable  
443/tcp closed https  
  
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds  

从上面的跟踪看,NSE‘http’库使用的默认User-Agent是“Mozilla/5.0(compatible;
Nmap Scripting Engine;http://nmap.org/book/nse.html)”.
可能由于某些安全原因,你需要更改user-agent,可使用下面方法.

offensive@security:~$ nmap -p 80,443 --script /home/offensive/nmap_nse/http-vuln-check_openssl.nse --script-args="http.useragent='Mozilla/5.0 (compatible [offensive@security])'" --script-trace 192.168.1.105 
  
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-30 06:08 EDT  
NSOCK INFO [0.2590s] nsi_new2(): nsi_new (IOD #1)  
NSOCK INFO [0.2600s] nsock_connect_tcp(): TCP connection requested to 192.168.1.105:80 (IOD #1) EID 8 
NSOCK INFO [0.2610s] nsock_trace_handler_callback(): Callback: CONNECT SUCCESS for EID 8 [192.168.1.105:80] 
NSE: TCP 192.168.1.106:59923 > 192.168.1.105:80 | CONNECT  
NSE: TCP 192.168.1.106:59923 > 192.168.1.105:80 | 00000000: 47 45 54 20 2f 61 72 63 74 69 63 66 69 73 73 69 GET /arcticfissi 
00000010: 6f 6e 2e 68 74 6d 6c 20 48 54 54 50 2f 31 2e 31 on.html HTTP/1.1  
00000020: 0d 0a 48 6f 73 74 3a 20 31 39 32 2e 31 36 38 2e   Host: 192.168.  
00000030: 31 2e 31 30 35 0d 0a 55 73 65 72 2d 41 67 65 6e 1.105  User-Agen  
00000040: 74 3a 20 4d 6f 7a 69 6c 6c 61 2f 35 2e 30 20 28 t: Mozilla/5.0 (  
00000050: 63 6f 6d 70 61 74 69 62 6c 65 20 5b 6f 66 66 65 compatible [offe  
00000060: 6e 73 69 76 65 40 73 65 63 75 72 69 74 79 5d 29 nsive@security])  
00000070: 0d 0a 43 6f 6e 6e 65 63 74 69 6f 6e 3a 20 63 6c   Connection: cl  
00000080: 6f 73 65 0d 0a 0d 0a                            ose      
  
NSOCK INFO [0.2610s] nsock_trace_handler_callback(): Callback: WRITE SUCCESS for EID 19 [192.168.1.105:80] 
NSE: TCP 192.168.1.106:59923 > 192.168.1.105:80 | SEND  
NSOCK INFO [0.2610s] nsock_read(): Read request from IOD #1 [192.168.1.105:80] (timeout: 8000ms) EID 26 
NSOCK INFO [0.2640s] nsock_trace_handler_callback(): Callback: READ SUCCESS for EID 26 [192.168.1.105:80] (392 bytes) 
NSE: TCP 192.168.1.106:59923 < 192.168.1.105:80 | 00000000: 48 54 54 50 2f 31 2e 31 20 32 30 30 20 4f 4b 0d HTTP/1.1 200 OK   
00000010: 0a 44 61 74 65 3a 20 54 75 65 2c 20 33 30 20 53  Date: Tue, 30 S  
00000020: 65 70 20 32 30 31 34 20 31 30 3a 30 38 3a 32 34 ep 2014 10:08:24  
00000030: 20 47 4d 54 0d 0a 53 65 72 76 65 72 3a 20 41 70  GMT  Server: Ap  
00000040: 61 63 68 65 2f 32 2e 32 2e 32 32 20 28 44 65 62 ache/2.2.22 (Deb  
00000050: 69 61 6e 29 0d 0a 4c 61 73 74 2d 4d 6f 64 69 66 ian)  Last-Modif  
00000060: 69 65 64 3a 20 54 75 65 2c 20 33 30 20 53 65 70 ied: Tue, 30 Sep  
00000070: 20 32 30 31 34 20 30 37 3a 33 30 3a 33 33 20 47  2014 07:30:33 G  
00000080: 4d 54 0d 0a 45 54 61 67 3a 20 22 65 31 31 38 31 MT  ETag: "e1181  
00000090: 2d 37 34 2d 35 30 34 34 33 35 62 64 38 36 62 30 -74-504435bd86b0  
000000a0: 32 22 0d 0a 41 63 63 65 70 74 2d 52 61 6e 67 65 2"  Accept-Range  
000000b0: 73 3a 20 62 79 74 65 73 0d 0a 43 6f 6e 74 65 6e s: bytes  Conten  
000000c0: 74 2d 4c 65 6e 67 74 68 3a 20 31 31 36 0d 0a 56 t-Length: 116  V  
000000d0: 61 72 79 3a 20 41 63 63 65 70 74 2d 45 6e 63 6f ary: Accept-Enco  
000000e0: 64 69 6e 67 0d 0a 43 6f 6e 6e 65 63 74 69 6f 6e ding  Connection  
000000f0: 3a 20 63 6c 6f 73 65 0d 0a 43 6f 6e 74 65 6e 74 : close  Content  
00000100: 2d 54 79 70 65 3a 20 74 65 78 74 2f 68 74 6d 6c -Type: text/html  
00000110: 0d 0a 0d 0a 3c 68 74 6d 6c 3e 0a 3c 68 65 61 64     <html> <head  
00000120: 3e 0a 3c 74 69 74 6c 65 3e 41 72 63 74 69 63 46 > <title>ArcticF  
00000130: 69 73 73 69 6f 6e 20 31 2e 30 3c 2f 74 69 74 6c ission 1.0</titl  
00000140: 65 3e 0a 3c 2f 68 65 61 64 3e 0a 3c 62 6f 64 79 e> </head> <body  
00000150: 3e 0a 3c 68 31 3e 57 65 6c 63 6f 6d 65 20 74 6f > <h1>Welcome to  
00000160: 20 41 72 63 74 69 63 46 69 73 73 69 6f 6e 20 31  ArcticFission 1  
00000170: 2e 30 3c 2f 68 31 3e 0a 3c 2f 62 6f 64 79 3e 0a .0</h1> </body>   
00000180: 3c 2f 68 74 6d 6c 3e 0a                         </html>   
  
NSE: TCP 192.168.1.106:59923 > 192.168.1.105:80 | CLOSE  
NSOCK INFO [0.2660s] nsi_delete(): nsi_delete (IOD #1)  
Nmap scan report for 192.168.1.105  
Host is up (0.00053s latency).  
PORT    STATE  SERVICE  
80/tcp  open   http  
|_http-vuln-check_openssl: Vulnerable  
443/tcp closed https  
  
Nmap done: 1 IP address (1 host up) scanned in 0.27 seconds  
local shortport = require "shortport" 
local http = require "http"  
local stdnse = require "stdnse"  
local string = require "string"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
      
    local uri = "/arcticfission.html"  
      
    local options = {headers={}}  
    options['headers']['User-Agent'] = "Mozilla/5.0 (compatible; ArcticFission)"  
      
    local response = http.get(host, port, uri, options)  
  
    if ( response.status == 200 ) then  
        local title = string.match(response.body, "<[Tt][Ii][Tt][Ll][Ee][^>]*>ArcticFission ([^<]*)</[Tt][Ii][Tt][Ll][Ee]>") 
  
        if ( title == "1.0" ) then  
            return "Vulnerable"  
        else  
            return "Not Vulnerable"  
        end  
    end     
end 

包装脚本

如果你想要发布脚本,有些重要的元数据需要提供,例如:描述、作者信息、证书,以便理解脚本的功能与影响力.

-- The Head Section --  
description = [[Sample script to detect a fictional vulnerability in a fictional ArcticFission 1.0 web server]] 
author = "iphelix"  
license = "Same as Nmap -- See http://nmap.org/book/man-legal.html"  
categories = {"default", "safe"}  
  
local shortport = require "shortport"  
local http = require "http"  
local stdnse = require "stdnse"  
local string = require "string"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
    local uri = "/arcticfission.html"  
    local options = {header={}}  
    options['header']['User-Agent'] = "Mozilla/5.0 (compatible; ArcticFission)"  
  
    local response = http.get(host, port, uri, options)  
  
    if ( response.status == 200) then  
        local title = string.match(response.body, "<[Tt][Ii][Tt][Ll][Ee]>ArcticFission ([^<]*)</[Tt][Ii][Tt][Ll][Ee]>") 
  
        if ( title == "1.0" ) then  
            return "Vulnerable"  
        else  
            return "Not Vulnerable"  
        end  
    end  
end  

你现在可能想写入一些NSE文档格式的说明。脚本文档可能包含一些可能会被文档系统处理的特殊标识。(例如@output表示脚本输出,@args表示脚本参数,@usage表示简单的命令行参数,等)

-- The Head Section --  
description = [[Sample script to detect a fictional vulnerability in a fictional ArcticFission 1.0 web server]] 
  
---  
-- @usage  
-- nmap --script http-vuln-check <target>  
-- @output  
-- PORT    STATE  SERVICE  
-- 80/tcp  open   http  
-- |_http-vuln-check_packaging: Vulnerable  
  
  
author = "iphelix"  
license = "Same as Nmap -- See http://nmap.org/book/man-legal.html"  
categories = {"default", "safe"}  
  
local shortport = require "shortport"  
local http = require "http"  
local stdnse = require "stdnse"  
local string = require "string"  
  
-- The Rule Section --  
portrule = shortport.http  
  
-- The Action Section --  
action = function(host, port)  
    local uri = "/arcticfission.html"  
    local options = {header={}}  
    options['header']['User-Agent'] = "Mozilla/5.0 (compatible; ArcticFission)"  
  
    local response = http.get(host, port, uri, options)  
  
    if ( response.status == 200) then  
        local title = string.match(response.body, "<[Tt][Ii][Tt][Ll][Ee]>ArcticFission ([^<]*)</[Tt][Ii][Tt][Ll][Ee]>") 
  
        if ( title == "1.0" ) then  
            return "Vulnerable"  
        else  
            return "Not Vulnerable"  
        end  
    end  
end  

解析输出

使用自定义的脚本检测完成后,我们还需要解析产生的结果,以易理解的方式输出报告。不幸的是,‘gnamp’输出格式不支持脚本输出,所以我们选择解析‘xml’格式的输出。

#!/usr/bin/env python  
# nmap-xml-parse by iphelix  
  
import sys  
from xml.dom.minidom import parse  
  
  
def main():  
    if len(sys.argv) != 2:  
        print "Usage: %s nmap_output.xml" % sys.argv[0]  
        sys.exit(1)  
  
    nmap = parse(sys.argv[1])  
  
    for host in nmap.getElementsByTagName("host"):  
        addresses = [addr.getAttribute("addr")  
                     for addr in host.getElementsByTagName("address")]  
  
        for port in host.getElementsByTagName("port"):  
            portid = port.getAttribute("portid")  
  
            for script in port.getElementsByTagName("script"):  
                if script.getAttribute("id") == "http-vuln-check_packaging":  
                    output = script.getAttribute("output")  
  
                    for address in addresses:  
                        print "%s,%s,%s" % (address, portid, output)  
  
if __name__ == "__main__":  
    main() 

漏洞管理

上述漏洞发现脚本有些问题。首先,它没有漏洞相关的描述信息,其次,完成扫描后,你需要编写脚本解析整个扫描结果。上面的这些,可以用Nmap的库‘vulns’进行处理。

NSE漏洞库

NSE漏洞库DjalalHarouniHenriDoreau开发,目的是标准化呈现与管理漏洞。

-- The Head Section --  
description = [[Sample script to detect a fictional vulnerability in a fictional ArcticFission 1.0 web server]] 
  
---  
-- @usage  
-- nmap --script http-vuln-check <target>  
-- @output  
-- PORT    STATE  SERVICE  
-- 80/tcp  open   http  
-- |_http-vuln-check_packaging: Vulnerable  
-- |   VULNERABLE  
-- |   ArcticFission 1.0 Vulnerability  
-- |     State: VULNERABLE  
-- |     IDs: CVE:CVE-XXXX-XX  
-- |     References:  
-- |_      http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-XXXX-XX  
  
  
  
author = "iphelix"  
license = "Same as Nmap -- See http://nmap.org/book/man-legal.html"  
categories = {"default", "safe"}  
  
local shortport = require "shortport"  
local http = require "http"  
local stdnse = require "stdnse"  
local string = require "string"  
local vulns = require "vulns"  
  
  
-- The Rule Section --  
portrule = shortport.http 
-- The Action Section --  
action = function(host, port)  
  
    -- The Vuln Definition Section --  
    local vuln = {  
        title = "ArcticFission 1.0 Vulnerability",  
        state = vulns.STATE.NOT_VULN,  
        IDS = { CVE = 'CVE-XXXX-XXX' }  
    }  
    local report = vulns.Report:new(SCRIPT_NAME, host, port)  
  
    local uri = "/arcticfission.html"  
    local options = {header={}}  
    options['header']['User-Agent'] = "Mozilla/5.0 (compatible; ArcticFission)"  
  
    local response = http.get(host, port, uri, options)  
  
    if ( response.status == 200) then  
        local title = string.match(response.body, "<[Tt][Ii][Tt][Ll][Ee]>ArcticFission ([^<]*)</[Tt][Ii][Tt][Ll][Ee]>") 
  
        if ( title == "1.0" ) then  
            vuln.state = vulns.STATE.VULN  
        else  
            vuln.state = vulns.STATE.NOT_VULN  
        end  
    end  
  
    return report:make_output(vuln)  
end 

扫描结果如下:

offensive@security:~$ nmap -p 80,443 --script /home/offensive/nmap_nse/http-vuln-check_packaging.nse  192.168.1.105 
  
Starting Nmap 6.47 ( http://nmap.org ) at 2014-09-30 10:22 EDT  
Nmap scan report for localhost (192.168.1.105)  
Host is up (0.00053s latency).  
PORT    STATE  SERVICE  
80/tcp  open   http  
| http-vuln-check_packaging:   
|   VULNERABLE:  
|   ArcticFission 1.0 Vulnerability  
|     State: VULNERABLE  
|     IDs:  CVE:CVE-XXXX-XXX  
|     References:  
|_      http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-XXXX-XXX  
443/tcp closed https  
  
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds 

从这里获取了什么

我希望你能够对上面我提到的Nmap脚本感到兴奋。最好的办法就是学习库相关的文档,并编写一些复杂的脚本,不局限于httpNmap是一款强大的工具,强大的脚本库及开源的社区支持,会促使其变成一款强大的漏洞扫描器。感谢,Fyodor和所有的Nmap开发者。

参考链接

NmapNetwork Scanning

Lua

NmapAPI

NSELibraries

pwnmaps

NSEVulnerability Library

ListTCP and UDP port

[原始链接]writingnse
scripts for vulnerability scanning

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