1 1 00:00:00,210 --> 00:00:02,220 Network segmentation. 2 2 00:00:02,220 --> 00:00:03,930 In this lesson, we're going to go through 3 3 00:00:03,930 --> 00:00:05,520 and do a little bit of configuration 4 4 00:00:05,520 --> 00:00:07,410 of how you would do network segmentation 5 5 00:00:07,410 --> 00:00:09,600 and security within your network. 6 6 00:00:09,600 --> 00:00:11,070 Now, to do this, I'm going to be using 7 7 00:00:11,070 --> 00:00:13,500 an open source unified threat management appliance 8 8 00:00:13,500 --> 00:00:15,390 known as pfSense. 9 9 00:00:15,390 --> 00:00:16,710 You can download this yourself 10 10 00:00:16,710 --> 00:00:20,550 and install it in your own network at pfsense.org. 11 11 00:00:20,550 --> 00:00:22,950 Now, this lab is going to be focused on the installation 12 12 00:00:22,950 --> 00:00:25,260 and configuration issues that you might come across 13 13 00:00:25,260 --> 00:00:27,060 when you're doing this in the real world. 14 14 00:00:27,060 --> 00:00:29,280 To get started, I'm going to go into my lab environment, 15 15 00:00:29,280 --> 00:00:32,190 and I'm going to enter into the web application interface 16 16 00:00:32,190 --> 00:00:34,890 for this particular unified threat management system. 17 17 00:00:34,890 --> 00:00:36,960 I'm going to log in with my username and password, 18 18 00:00:36,960 --> 00:00:40,410 which in my case is admin, and the password of "Password." 19 19 00:00:40,410 --> 00:00:42,480 Now, once I'm in here, I want to go forward 20 20 00:00:42,480 --> 00:00:44,940 and look at the firewall ACLs. 21 21 00:00:44,940 --> 00:00:47,760 This firewall that we have has two different interfaces. 22 22 00:00:47,760 --> 00:00:50,490 It has an external one and an internal one. 23 23 00:00:50,490 --> 00:00:52,020 This might act like a router. 24 24 00:00:52,020 --> 00:00:53,610 On the external side, I have the internet. 25 25 00:00:53,610 --> 00:00:56,190 On the internal side, I have my local area network. 26 26 00:00:56,190 --> 00:00:57,810 This firewall is going to be screening 27 27 00:00:57,810 --> 00:01:00,030 any traffic coming in from the external network 28 28 00:01:00,030 --> 00:01:02,610 before it gets into my local network segment. 29 29 00:01:02,610 --> 00:01:04,080 This means that any traffic 30 30 00:01:04,080 --> 00:01:06,810 that matches my access control list can get through, 31 31 00:01:06,810 --> 00:01:09,180 and anything that's denied by my access control list 32 32 00:01:09,180 --> 00:01:10,470 will be rejected. 33 33 00:01:10,470 --> 00:01:13,470 So let's take a look at what rules we already have here. 34 34 00:01:13,470 --> 00:01:16,980 First, we're going to click on "Firewall," and then "Rules." 35 35 00:01:16,980 --> 00:01:19,320 From here, we can see on the WAN tab 36 36 00:01:19,320 --> 00:01:20,580 that there are several different types 37 37 00:01:20,580 --> 00:01:22,050 of traffic that's permitted. 38 38 00:01:22,050 --> 00:01:25,020 We have things like ICMP, which is ping traffic. 39 39 00:01:25,020 --> 00:01:27,960 We have DNS, which does domain name resolution. 40 40 00:01:27,960 --> 00:01:30,240 We have HTTP and HTTPS, 41 41 00:01:30,240 --> 00:01:31,830 which is going to allow web browsing. 42 42 00:01:31,830 --> 00:01:35,190 And we have SMTP, which is going to allow outbound email. 43 43 00:01:35,190 --> 00:01:36,960 Now notice all of these things 44 44 00:01:36,960 --> 00:01:39,060 are things that you would normally expect to see, 45 45 00:01:39,060 --> 00:01:40,710 and they all have forwarding rules. 46 46 00:01:40,710 --> 00:01:42,480 That means that traffic from these ports 47 47 00:01:42,480 --> 00:01:45,480 is going to be directed to a host inside the LAN. 48 48 00:01:45,480 --> 00:01:47,790 Now, all of these, except for ICMP that is. 49 49 00:01:47,790 --> 00:01:51,240 ICMP just has an allow rule, not a forwarding rule. 50 50 00:01:51,240 --> 00:01:53,280 Now, why are these forwarding rules in place? 51 51 00:01:53,280 --> 00:01:56,310 Well, because I'm setting up a DMZ. 52 52 00:01:56,310 --> 00:01:58,770 And so I'm going to have people from outside the network 53 53 00:01:58,770 --> 00:02:01,860 being able to go into my network using that forwarding, 54 54 00:02:01,860 --> 00:02:05,220 and then get to my DNS server or my HTTP server, 55 55 00:02:05,220 --> 00:02:08,850 or my HTTPS server, or my SMTP server. 56 56 00:02:08,850 --> 00:02:10,740 So now let's click on the LAN tab, 57 57 00:02:10,740 --> 00:02:12,270 which is the internal network. 58 58 00:02:12,270 --> 00:02:14,250 This is where I'm hosting those servers. 59 59 00:02:14,250 --> 00:02:16,620 Now notice here there is no egress filtering, 60 60 00:02:16,620 --> 00:02:18,000 which means there's nothing blocking 61 61 00:02:18,000 --> 00:02:19,680 anything from going out. 62 62 00:02:19,680 --> 00:02:21,960 Any type of traffic from a host on the LAN 63 63 00:02:21,960 --> 00:02:23,850 can go to any other endpoint, 64 64 00:02:23,850 --> 00:02:25,830 unless there's going to be a deny rule put in place 65 65 00:02:25,830 --> 00:02:27,960 by a higher level ACL. 66 66 00:02:27,960 --> 00:02:30,750 Now, if I click on the Firewall and click on NAT, 67 67 00:02:30,750 --> 00:02:31,583 you can see the host 68 68 00:02:31,583 --> 00:02:33,420 that I'm going to be sending this traffic to. 69 69 00:02:33,420 --> 00:02:35,550 Remember, I had that NAT forwarding going on. 70 70 00:02:35,550 --> 00:02:38,190 So here you see DNS is going to go to the server 71 71 00:02:38,190 --> 00:02:41,250 located at 10.1.0.1. 72 72 00:02:41,250 --> 00:02:44,130 If you look at the web, HTTP and HTTPS, 73 73 00:02:44,130 --> 00:02:47,747 this is going to my Apache web server at 10.1.0.10, 74 74 00:02:47,747 --> 00:02:52,747 and my SMTP is going to go to my email server at 10.1.0.2. 75 75 00:02:53,820 --> 00:02:56,430 So is there any issues with this? 76 76 00:02:56,430 --> 00:02:58,200 Well, there is an issue here. 77 77 00:02:58,200 --> 00:03:01,470 Putting all these things in the same segment is pretty risky 78 78 00:03:01,470 --> 00:03:03,660 because a web server, for instance, is going to be exposed 79 79 00:03:03,660 --> 00:03:05,730 to a large number of vulnerabilities and exploits 80 80 00:03:05,730 --> 00:03:08,310 because they can have things like cross-site scripting. 81 81 00:03:08,310 --> 00:03:10,350 They can have things like remote code execution 82 82 00:03:10,350 --> 00:03:12,180 and all sorts of other exploits. 83 83 00:03:12,180 --> 00:03:15,000 So if somebody was able to compromise that one server, 84 84 00:03:15,000 --> 00:03:17,400 they can then pivot over to the SMTP server, 85 85 00:03:17,400 --> 00:03:20,670 or over to the DNS server and take advantage of those too. 86 86 00:03:20,670 --> 00:03:23,190 So we probably want to add some segmentation, 87 87 00:03:23,190 --> 00:03:24,300 and that's what we're going to focus on 88 88 00:03:24,300 --> 00:03:26,370 here through the rest of this lab. 89 89 00:03:26,370 --> 00:03:29,040 Now, to configure this firewall so that my web server 90 90 00:03:29,040 --> 00:03:31,740 is put into an isolated demilitarized zone, 91 91 00:03:31,740 --> 00:03:33,900 I need to be able to separate it from the other hosts, 92 92 00:03:33,900 --> 00:03:34,733 and I'm going to do this 93 93 00:03:34,733 --> 00:03:37,470 by creating a third interface on the firewall. 94 94 00:03:37,470 --> 00:03:39,480 Now, to do this within pfSense, 95 95 00:03:39,480 --> 00:03:42,240 I'm going to go to "Interfaces" and then "Assignments." 96 96 00:03:42,240 --> 00:03:44,130 From here, I'm going to click the "Add" button, 97 97 00:03:44,130 --> 00:03:45,871 next to the unused interface. 98 98 00:03:45,871 --> 00:03:47,340 Now from the menu bar, 99 99 00:03:47,340 --> 00:03:51,780 I can select interfaces and then OPT1 for option one. 100 100 00:03:51,780 --> 00:03:54,210 I'm going to check the enable interface box, 101 101 00:03:54,210 --> 00:03:57,270 and I'm going to go in and select "Static IPv4" 102 102 00:03:57,270 --> 00:04:00,000 for my IPv4 configuration type. 103 103 00:04:00,000 --> 00:04:02,700 When I go down there, I'm going to put in the IPv4 address 104 104 00:04:02,700 --> 00:04:06,450 of 10.1.254.254, 105 105 00:04:06,450 --> 00:04:09,510 and I'm going to select 24 from the list box. 106 106 00:04:09,510 --> 00:04:12,360 Now I'm going to save my changes and apply those changes. 107 107 00:04:12,360 --> 00:04:14,640 This is going to enable that interface 108 108 00:04:14,640 --> 00:04:17,730 on the firewall using that IP address. 109 109 00:04:17,730 --> 00:04:20,550 Next I'm going to go to firewall and then click "Nat." 110 110 00:04:20,550 --> 00:04:22,320 And here I'm going to click the edit button, 111 111 00:04:22,320 --> 00:04:25,890 that pen icon, on the HTTP forwarding rule. 112 112 00:04:25,890 --> 00:04:30,780 I want to redirect that IP value to 10.1.254.10, 113 113 00:04:30,780 --> 00:04:33,630 and change my description of HTTP forwarding 114 114 00:04:33,630 --> 00:04:36,510 to the DMZ and then save it. 115 115 00:04:36,510 --> 00:04:39,390 Next, I'm going to edit the HTTPS forwarding rule. 116 116 00:04:39,390 --> 00:04:43,120 Again, I'm going to type in 10.1.254.10, 117 117 00:04:43,120 --> 00:04:45,600 and I'm going to change the description to HTTPS forwarding 118 118 00:04:45,600 --> 00:04:49,290 to the DMZ and click "Save," and then apply changes. 119 119 00:04:49,290 --> 00:04:51,000 So at this point, 120 120 00:04:51,000 --> 00:04:53,400 you can now see we have a couple of rules here. 121 121 00:04:53,400 --> 00:04:57,810 You can see we have the SMTP rule going to 10.1.0.2. 122 122 00:04:57,810 --> 00:04:59,040 It's using forwarding. 123 123 00:04:59,040 --> 00:05:03,523 Then we have HTTPS and HTTP both going to 10.1.254.10, 124 124 00:05:04,560 --> 00:05:07,050 using that forwarding rule to the DMZ. 125 125 00:05:07,050 --> 00:05:09,060 And finally, we have DNS still going 126 126 00:05:09,060 --> 00:05:12,330 to the DNS server located at 10.1.0.1. 127 127 00:05:12,330 --> 00:05:14,220 Next, I need to set up my logging. 128 128 00:05:14,220 --> 00:05:17,100 So anything that's going through this firewall gets logged. 129 129 00:05:17,100 --> 00:05:18,390 So what am I going to log? 130 130 00:05:18,390 --> 00:05:19,470 Well, let's go up here 131 131 00:05:19,470 --> 00:05:23,160 and click on "Status," "System Logs," and "Settings." 132 132 00:05:23,160 --> 00:05:24,540 Then scroll down, 133 133 00:05:24,540 --> 00:05:26,587 and click the check button next to 134 134 00:05:26,587 --> 00:05:29,160 "Log packets matched from the default block rules" 135 135 00:05:29,160 --> 00:05:30,390 in the rule set. 136 136 00:05:30,390 --> 00:05:32,910 This means anything that's blocked is going to get logged. 137 137 00:05:32,910 --> 00:05:34,890 All right, so everything's looking good now, 138 138 00:05:34,890 --> 00:05:36,930 but we still have one more step. 139 139 00:05:36,930 --> 00:05:39,690 We haven't configured the web server to move itself 140 140 00:05:39,690 --> 00:05:42,570 into the DMZ, because we changed the IP address, 141 141 00:05:42,570 --> 00:05:45,390 so now we have to give that web server that new IP address 142 142 00:05:45,390 --> 00:05:47,802 of 10.1.254.10. 143 143 00:05:47,802 --> 00:05:50,580 To do this, I'm going to log into my web server. 144 144 00:05:50,580 --> 00:05:52,200 I'm going to click on the network icon, 145 145 00:05:52,200 --> 00:05:55,560 and then select the wired connected, and the wired settings. 146 146 00:05:55,560 --> 00:05:58,440 From here, I'm going to turn the wired connection off, 147 147 00:05:58,440 --> 00:06:01,140 click the cog icon to be able to go into settings, 148 148 00:06:01,140 --> 00:06:05,250 and then set IPv4 tab to set static manual IP address. 149 149 00:06:05,250 --> 00:06:10,230 And I'm going to give the address of 10.1.254.10/24, 150 150 00:06:11,160 --> 00:06:15,420 with a default gateway of 10.1.254.254. 151 151 00:06:15,420 --> 00:06:17,910 Once I've done that, I can click that slider button 152 152 00:06:17,910 --> 00:06:19,740 to turn the wired connection back on 153 153 00:06:19,740 --> 00:06:21,450 and close the connection window. 154 154 00:06:21,450 --> 00:06:24,990 All right, at this point, we should have our DMZ configured 155 155 00:06:24,990 --> 00:06:28,320 with the web server sitting in the DMZ, the DNS server 156 156 00:06:28,320 --> 00:06:31,050 and the SMTP server sitting on the internal network, 157 157 00:06:31,050 --> 00:06:33,420 and the external network, being the internet, 158 158 00:06:33,420 --> 00:06:35,250 out on that external interface. 159 159 00:06:35,250 --> 00:06:37,650 Let's go ahead and test our segmentation. 160 160 00:06:37,650 --> 00:06:38,760 First, I'm going to verify 161 161 00:06:38,760 --> 00:06:41,640 that we can browse the server as normal if we're doing this 162 162 00:06:41,640 --> 00:06:45,540 from our PC, which is inside of that local area network. 163 163 00:06:45,540 --> 00:06:47,190 Well, to do this, I'm going to go to 164 164 00:06:47,190 --> 00:06:52,190 www.515support.com/dvwa, and www.515support.com/multitilde. 165 165 00:06:57,720 --> 00:07:01,170 Notice both of these browse with no issues at all. 166 166 00:07:01,170 --> 00:07:03,630 Next, I'm going to see if this server is vulnerable 167 167 00:07:03,630 --> 00:07:05,730 to a reverse shell attack vector. 168 168 00:07:05,730 --> 00:07:08,040 To do this, I'm going to go into Metasploit, 169 169 00:07:08,040 --> 00:07:09,510 like I've used in other lessons, 170 170 00:07:09,510 --> 00:07:12,240 and I'm going to use the exploit multi handler. 171 171 00:07:12,240 --> 00:07:14,430 And then I'm going to type in "Exploit." 172 172 00:07:14,430 --> 00:07:16,590 From here, I'm going to run the "Curl" command 173 173 00:07:16,590 --> 00:07:18,930 and see if I can establish a reverse shell. 174 174 00:07:18,930 --> 00:07:22,140 So if I type in "curl --user" 175 175 00:07:22,140 --> 00:07:23,310 and then the user I'm going to use, 176 176 00:07:23,310 --> 00:07:26,790 in this case sam:password, 177 177 00:07:26,790 --> 00:07:28,200 and the site I'm trying to do this to, 178 178 00:07:28,200 --> 00:07:33,200 http://www.515support.com/webdev/get.php. 179 179 00:07:36,540 --> 00:07:38,940 Now, this is not going to work this time. 180 180 00:07:38,940 --> 00:07:41,520 This means there's no interpreter shells being open, 181 181 00:07:41,520 --> 00:07:44,280 because our ACL should have been configured 182 182 00:07:44,280 --> 00:07:47,100 to only allow incoming connections on each interface. 183 183 00:07:47,100 --> 00:07:50,100 So it's going to block OPT1 when the web server 184 184 00:07:50,100 --> 00:07:52,440 is trying to initiate a new connection to it. 185 185 00:07:52,440 --> 00:07:54,750 However, it can reply to web sessions 186 186 00:07:54,750 --> 00:07:56,520 that external hosts have started. 187 187 00:07:56,520 --> 00:07:59,340 So when I tried to access it to the web browser, 188 188 00:07:59,340 --> 00:08:01,800 I made a request and then it responded. 189 189 00:08:01,800 --> 00:08:03,720 But in this case, with the curl command, 190 190 00:08:03,720 --> 00:08:06,930 I'm trying to have the server send that out initially 191 191 00:08:06,930 --> 00:08:09,660 without a request coming, and that is why we're showing 192 192 00:08:09,660 --> 00:08:12,030 that this reverse shell is not going to work. 193 193 00:08:12,030 --> 00:08:12,863 All right, 194 194 00:08:12,863 --> 00:08:15,030 let's go back and take a look at our firewall logs now. 195 195 00:08:15,030 --> 00:08:16,470 If I go back into my firewall, 196 196 00:08:16,470 --> 00:08:20,400 I can click on "Status," "System Logs," and then "Firewall." 197 197 00:08:20,400 --> 00:08:22,980 Note here you can see the log view has been configured 198 198 00:08:22,980 --> 00:08:25,530 with the most recent events at the top. 199 199 00:08:25,530 --> 00:08:28,560 Observe the rule at the top for regular HTTP browsing. 200 200 00:08:28,560 --> 00:08:32,670 This came from 192.168.2.192, 201 201 00:08:32,670 --> 00:08:37,670 and it went to the web server at 10.1.254.10 over port 80. 202 202 00:08:37,830 --> 00:08:40,500 Now, observe the default blocking rule that we saw here. 203 203 00:08:40,500 --> 00:08:44,670 10.1.254.10 is not allowed to establish a connection 204 204 00:08:44,670 --> 00:08:49,670 to 192.168.2.192 over port 8080. 205 205 00:08:50,160 --> 00:08:52,860 This is what we try to do when I use that curl command. 206 206 00:08:52,860 --> 00:08:55,170 Essentially, I was trying to go from the web server 207 207 00:08:55,170 --> 00:08:58,260 over to the client PC in the internal network, 208 208 00:08:58,260 --> 00:09:01,230 and because of this DMZ rule, it's going to block that. 209 209 00:09:01,230 --> 00:09:02,760 Now, if I click on that cross, 210 210 00:09:02,760 --> 00:09:06,570 I can see additional details about this hidden default rule. 211 211 00:09:06,570 --> 00:09:07,680 So as you can see here, 212 212 00:09:07,680 --> 00:09:09,930 we have successfully isolated our web server 213 213 00:09:09,930 --> 00:09:12,300 from other hosts on the internal network, 214 214 00:09:12,300 --> 00:09:14,010 while still allowing it to have access 215 215 00:09:14,010 --> 00:09:16,800 from those hosts to the web server when they need it 216 216 00:09:16,800 --> 00:09:18,090 but preventing the web server 217 217 00:09:18,090 --> 00:09:20,310 from getting back to those hosts. 218 218 00:09:20,310 --> 00:09:23,487 So you can see how we can add segmentation here to make sure 219 219 00:09:23,487 --> 00:09:26,190 that the devices in the internal network are protected 220 220 00:09:26,190 --> 00:09:29,850 from the external network and from that untrusted DMZ. 221 221 00:09:29,850 --> 00:09:32,160 Now, we've talked about jump boxes as well, 222 222 00:09:32,160 --> 00:09:34,680 and you could configure a jump box on the DMZ 223 223 00:09:34,680 --> 00:09:36,450 as the single point of entry. 224 224 00:09:36,450 --> 00:09:39,930 Essentially, you would get SSH access into that jump box 225 225 00:09:39,930 --> 00:09:42,840 in the DMZ, and then from that jump box in the DMZ 226 226 00:09:42,840 --> 00:09:44,550 you could access all of the other hosts 227 227 00:09:44,550 --> 00:09:47,850 inside the DMZ because it's in that environment already. 228 228 00:09:47,850 --> 00:09:49,410 This would be a good way to set things up, 229 229 00:09:49,410 --> 00:09:52,050 especially if you configure a forward proxy connection 230 230 00:09:52,050 --> 00:09:54,360 to those different application servers. 231 231 00:09:54,360 --> 00:09:56,430 All right, so I hope you've enjoyed this lesson 232 232 00:09:56,430 --> 00:09:59,580 as we got a little hands-on using unified threat management 233 233 00:09:59,580 --> 00:10:00,450 and firewalls, 234 234 00:10:00,450 --> 00:10:03,200 and going through some configurations for segmentation.