08-19-2004 09:08 AM - edited 02-20-2020 11:34 PM
Hi,
I seem to be stuck with this issue. I scanned my firewall using www.grc.com. After the scan I seem to have a number of ports open aside from the ones that need to be open like 80 and 25. The port numbers that are currently open are 53,88,135,139,143,389,445,464,593,636,691,993,995,1026 & 1029. When I look at my config, I can`t seem to find anything that relates to those ports. I`d Like to close to ports, but I`m not sure if they are needed for the VPN. Here is a copy of my config. If anyone can point me in the right direction that would be greatly appreciated.
Thanks
08-19-2004 09:49 AM
Hi,
You have an access-list acl_out that allows any host to access your inside hosts with TCP. So you don't have any tcp protocol restriction.
access-list acl_out permit tcp any host x.y.3.54
access-list acl_out permit tcp any host x.y.3.53
static (inside,outside) X.X.X.X 192.168.0.2 netmask 255.255.255
static (inside,outside) X.X.X.X 192.168.0.83 netmask 255.255.25
Solution: You just have to create an access-list that filtere more specific.
example:
access-list acl-out permit udp any host MyPublicIPVPN eq isakmp
access-list acl-out permit esp any host MyPublicIPVPN
access-list acl-out permit ah any host MyPublicIPVPN
access-list acl_out permit tcp any host x.y.3.54 eq 80
access-list acl_out permit tcp any host x.y.3.54 eq 25
access-list acl_out permit tcp any host x.y.3.53 eq www
access-list acl_out permit tcp any host x.y.3.53 eq 25
The first 3 lines are for VPN, it allows all VPN Client to connect, the other 4 that follows are examples for smtp and www access-lists.
sincerly
Patrick
08-19-2004 10:19 AM
So basically, if I understand this correctly, I`m basically wide open?
If I add the example you just gave me I should be fine? Or can I just remove the like access-list acl_out permit tcp any host x.y.3.54 ?
Thanks for your help
08-19-2004 10:41 AM
Yes, you are right you are wide open for anybody with TCP. The only limitation is your Servers security.
Yes you have to remove the old access-list lines but add the new ones before and after that remove the old ones with a NO statment:
no access-list acl_out permit tcp any host x.y.3.54
no access-list acl_out permit tcp any host x.y.3.53
sincerly
Patrick
08-24-2004 06:50 AM
Thanks for you help Patrick.
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