基于OSSIM平台的漏洞扫描详解
Ossim 中漏洞扫描详解
Openvas是一套开源漏洞扫描系统，如果手动搭建需要复杂的过程，花费不少人力和时间成本，因为它是套免费的漏洞扫描系统，功能上不逊色于商业版的漏洞扫描器，受到不少用户的青睐，下表对比了NeXpose、RSAS和启明的漏洞扫描器的主要功能。
有了以上背景之后，下文主要针对OSSIM平台下如何以图形化方式操作漏洞扫描的过程。
准备工作：首先确保没有运行的扫描进程和任务
扫描漏洞同时升级漏洞库会导致升级失败。
第一步：同步插件
#openvas-nvt-sync
[i] This script synchronizes an NVT collection with the 'OpenVAS NVT Feed'.
[i] The 'OpenVAS NVT Feed' is provided by 'The OpenVAS Project'.
[i] Online information about this feed: 'http://www.openvas.org/openvas-nvt-feed.html'.
[i] NVT dir: /var/lib/openvas/plugins
[i] Will use rsync
[i] Using rsync: /usr/bin/rsync
[i] Configured NVT rsync feed: rsync://feed.openvas.org:/nvt-feed
OpenVAS feed server - http://www.openvas.org/
This service is hosted by Intevation GmbH - http://intevation.de/
All transactions are logged.
Please report synchronization problems to openvas-feed@intevation.de.
If you have any other questions, please use the OpenVAS mailing lists
or the OpenVAS IRC chat. See http://www.openvas.org/ for details.
receiving incremental file list
deleting gb_openssl_38562.nasl.asc
deleting gb_openssl_38562.nasl
./
COPYING
588 100% 574.22kB/s 0:00:00 (xfer#1, to-check=13347/13355)
COPYING.GPLv2
18002 100% 17.17MB/s 0:00:00 (xfer#2, to-check=13346/13355)
COPYING.files
1819904 100% 1.77MB/s 0:00:00 (xfer#3, to-check=13345/13355)
DDI_Directory_Scanner.nasl
32957 100% 32.74kB/s 0:00:00 (xfer#4, to-check=13342/13355)
DDI_Directory_Scanner.nasl.asc
198 100% 0.20kB/s 0:00:00 (xfer#5, to-check=13341/13355)
... ...
同步数万个插件时间比较长，消耗资源不大，可以去喝杯咖啡啦，或者了解一下插件的组成。
表1 Openvas主要脚本分类及分布情况
规则名称 | 数量 | 备注 |
IIS_frontpage_DOS_2.nasl | 1 | |
phpbb | 8 | |
RA_ssh_detect RA_www_css RA_www_detect | 3 | |
RHSA_2009_03** | 279 | Redhat Security Advisory |
3com_switches | 1 | |
weblogic* | 3 | |
cisco_ids cisco_*** ciscoworks | 16 | |
awstats | 4 | |
apache | 23 | |
DDI | 30 | |
EZ_hotscripts | 3 | |
anti_nessus | 1 | |
basilix | 8 | |
bluecoat | 1 | |
bugbear | 3 | |
bugzilla | 9 | |
ca_unicenter | 2 | |
cacti | 5 | |
calendar | 3 | |
Spoll_7_5_sql_injection | 2 | |
avaya_switches | 1 | |
citrix | 8 | |
clamav | 2 | |
CUPS | 12 | |
cutenews | 12 | |
checkpoint | 6 | |
cheopsNG | 4 | |
cvstrac | 24 | |
DB2 | 4 | |
deb_*.nasl | 2595 | Debian Linux |
DNS | 5 | |
deluxeBB | 3 | |
eftp | 3 | |
ls exchange* | ||
exchange | 2 | |
fcore | 684 | |
find_service | 5 | |
fortigate | 1 | |
freebsd | 2009 | |
ftp | 30 | |
gb_CESA | 1528 | |
gb_RHSA | 871 | |
gb_adobe | 167 | |
gb_apple | 70 | |
gb_baofeng_storm | 3 | |
gb_bpsoft | 3 | |
gb_clamav | 16 | |
gb_ccproxy | 2 | |
gb_clamav | 16 | |
gb_fedora | 4679 | |
gb_google | 162 | |
gb_hp_ux | 242 | HP-UNIX |
gb_ibm_db2 | 27 | |
gb_ibm_websphere | 8 | |
gb_ibm_tivoli | 5 | |
gb_ibm_was | 16 | |
gb_ibm_lotus | 10 | |
gb_mandriva | 1684 | |
gb_java | 2 | |
gb_kaspersky | 6 | |
gb_google_chrome | 153 | |
gb_foxmail | 2 | |
gb_fsecure | 7 | |
gb_ms | 155 | Windows 相关 |
gb_ubuntu | 1261 | |
gb_samba | 12 | |
gb_sun_java | 35 | |
gb_wireshark | 87 | |
glsa | 1727 | |
gb_vmware | 41 | |
IIS | 20 | |
lotus | 5 | |
ipswitch | 5 | |
mysql | 5 | |
gb_nmap | 187 | |
nortel | 7 | |
nagios | 5 | |
openssh | 4 | |
oscommerce | 5 | |
postgresql | 5 | |
phpgroupware | 12 | |
phpmyadmin | 7 | |
phpbb | 8 | |
smb | 52 | |
sendmail | 15 | |
suse | 65 | |
ssh | 11 | |
smtp | 9 | |
Ubuntu | 179 | |
tomcat | 6 | |
tftp | 11 | |
wu_ftpd | 6 |
第二步：更新插件（做这一步操作，建议在轻负载下进行）
#perl /usr/share/ossim/scripts/vulnmeter/updateplugins.pl migrate /* 比较消耗CPU和磁盘I/O */
2015-09-07 07:27:33 Framework profile has been found...
2015-09-07 07:27:33 Deleting all tasks in 192.168.11.150 ...
2015-09-07 07:27:33 updateplugins: configured to not updateplugins
2015-09-07 07:27:33 updateplugins: configured to not repair DB
2015-09-07 07:27:33 BEGIN - DUMP PLUGINS
2015-09-07 07:29:01 FINISH - DUMP PLUGINS [ Process took 88 seconds ]
2015-09-07 07:29:01 BEGIN - IMPORT PLUGINS
2015-09-07 07:30:00 FINISH - IMPORT PLUGINS [ 40473 plugins - Process took 59 seconds ]
2015-09-07 07:30:00 BEGIN - UPDATE CATEGORIES
2015-09-07 07:30:00 FINISH - UPDATE CATEGORIES [ Process took 0 seconds ]
2015-09-07 07:30:00 BEGIN - UPDATE FAMILIES
2015-09-07 07:30:00 FINISH - UPDATE FAMILIES [ Process took 0 seconds ]
2015-09-07 07:30:00 BEGIN - UPDATE OPENVAS_PLUGINS
2015-09-07 07:30:03 FINISH - UPDATE OPENVAS_PLUGINS [ Process took 3 seconds ]
2015-09-07 07:30:03 BEGIN - UPDATE NESSUS_PREFERENCES
2015-09-07 07:30:03 show tables like "vuln_nessus_preferences_defaults"
2015-09-07 07:30:03 updateprefs: Getting plugin preferences
2015-09-07 07:30:05 FINISH - UPDATE NESSUS_PREFERENCES [ Process took 2 seconds ]
2015-09-07 07:30:06 Creating Deep profile...
2015-09-07 07:30:06 Filling categories...............
2015-09-07 07:30:06 Done
2015-09-07 07:30:06 Filling families.............................................................
2015-09-07 07:30:06 Done
2015-09-07 07:30:06 Filling plugins...
2015-09-07 07:30:13 Filling preferences in Alienvault DB...
2015-09-07 07:30:14 Done
2015-09-07 07:30:14 Deep profile inserted
2015-09-07 07:30:15 Creating Default profile...
2015-09-07 07:30:15 Filling categories...............
2015-09-07 07:30:15 Done
2015-09-07 07:30:15 Filling families.............................................................
2015-09-07 07:30:15 Done
2015-09-07 07:30:15 Filling plugins...
2015-09-07 07:30:23 Filling preferences in Alienvault DB...
2015-09-07 07:30:24 Done
2015-09-07 07:30:24 Default profile inserted
2015-09-07 07:30:24 Creating Ultimate profile...
2015-09-07 07:30:24 Filling categories...............
2015-09-07 07:30:24 Done
2015-09-07 07:30:24 Filling families.............................................................
2015-09-07 07:30:24 Done
2015-09-07 07:30:24 Filling plugins...
2015-09-07 07:30:32 Filling preferences in Alienvault DB...
2015-09-07 07:30:33 Done
2015-09-07 07:30:33 Ultimate profile inserted
2015-09-07 07:30:33 BEGIN - UPDATE PORT SCANNER
2015-09-07 07:30:35 FINISH - UPDATE PORT SCANNER [ Process took 2 seconds ]
Updating plugin_sid vulnerabilities scanner ids
plugins fetched
Updating...
Script id:94151, Name:IT-Grundschutz M4.288: Sichere Administration von VoIP-Endger?ten, Priority:0
Script id:703073, Name:Debian Security Advisory DSA 3073-1 (libgcrypt11 - security update), Priority:1
Script id:804624, Name:Adobe Reader Plugin Signature Bypass Vulnerability (Windows), Priority:2
Script id:868149, Name:Fedora Update for kernel FEDORA-2014-9959, Priority:5
Script id:95048, Name:IT-Grundschutz M5.145: Sicherer Einsatz von CUPS, Priority:0
Script id:842216, Name:Ubuntu Update for linux USN-2616-1, Priority:4
Script id:105036, Name:Open××× Detection, Priority:0
Script id:868005, Name:Fedora Update for audacious-plugins FEDORA-2014-8183, Priority:1
Script id:869350, Name:Fedora Update for springframework FEDORA-2015-6862, Priority:5
… …
Script id:105084, Name:Multiple ManageEngine Products Arbitrary File Upload Vulnerability, Priority:3
Script id:867751, Name:Fedora Update for python-keystoneclient FEDORA-2014-5555, Priority:3
Script id:882209, Name:CentOS Update for nss CESA-2015:1185 centos6, Priority:2
Script id:842209, Name:Ubuntu Update for libmodule-signature-perl USN-2607-1, Priority:5
经过一刻钟等待终于更新完成。注意，该过程需要一气呵成，中途不能强制退出。
下面用时间轴表示每个步骤的演进顺序和所花费的时间，如下图所示。从某日的00:34:34开始到00:38:50结束的过程。
如果有些用户不习惯在CLI下操作升级命令，这一工作同样可以在WebUI中完成。
第三步：验证更新
我们看到最后一行显示总数为40473，这个数值和下载的插件数量一直，代表升级完成。
注意：漏洞升级视频大家可访问：http://www.tudou.com/programs/view/kyTmc42Ky14/
第四步：开始漏洞扫描-定制策略
首先扫描资产，建立资源池，这里就不详细介绍。在OSSIM系统里默认定义了三种策略，默认为Default,该策略最为常用。
如果需要更改策略，请点击CREATE NEW PROFILE按钮。
接着开始扫描，填写任务名称，选择Sensor,选择策略，选择资源池内的主机，最后点击新建任务按钮。
扫描准备
漏洞扫描时那些进程最繁忙？
Htop是Linux系统中的一个互动的进程查看工具，该命令可以帮助管理员了解扫描发生的变化。#htop -d 50
一次扫描多少机器合适？
如果所监控网段服务器数量超过25台，这里假设是100台，那么至少分4次扫描，例如直接输入"192.168.11.0/24"，这样表示一个网段，那么OSSIM系统负载将会明显增大，扫描等待时间明显延长，可能会长达数天，直到超过一个计划任务的周期，这样可能造成一个恶性循环，直到拖垮整个系统。
进过300多分钟都没有结束的任务最后逃脱不了失败的命运。
扫描结果分析
不过在分析时，谈到"过时"的漏洞问题，在一些古老些操作系统Windows NT/2000、Solaris7/8、Linux（2.2 、2.4内核）曾经存在的那些系统漏洞、网络服务器漏洞，在现代系统中已经绝迹，受影响系统已经被修复，这种漏洞变得没有任何价值。对这些系统进行漏洞扫描变得没有意义。
