Full Disclosure mailing list archives

Re: server security


From: "Elazar Broad" <elazar () hushmail com>
Date: Fri, 22 Jun 2012 11:10:35 -0400

+1

The less an attacker knows about your infrastructure the better, as long as you are not solely relying on that 
obscurity to protect said infrastructure. Consider this: the more an attacker has to poke around because your aren't 
running certain services on their default port, or say disabling client scripting on your .NET Regex validator so that 
the validation expression isn't exposed in the page, the more noise said attacker is going to make while performing 
reconnaissance, and the better the chance that they will be detected by any detective controls that are in place.

My .0002

elazar

On Thursday, June 21, 2012 at 3:26 PM, Thor (Hammer of God) <thor () hammerofgod com> wrote:

I completely agree with Gage.  The way I see it, security through 
obscurity is perfectly valid as long as the control remains 
obscured.  I think the "anyone can just scan your ports" is 
somewhat specious in that most (if not something like 99% or so 
(unqualified opinion of course)) traffic is simply noise and scans 
for standard ports.  This is particularly true when it matters 
most: during a worm outbreak or a newly published vulnerability.  
Attackers simply don't have the time nor the inclination to go 
through and perform slow and loud scans when they can quickly move 
on to the next target.  If 90% of the targets have services on the 
default ports, then it makes far more sense to just go after the 
easily targets.  

Perfect case-in-point is the recent RDP unpleasantness.   Non-
standard port deployments were automatically removed from the 
target scans for 3389.  I don't see how any can argue against the 
security value of such a configuration.

t  



Timothy "Thor"  Mullen
www.hammerofgod.com
Thor's Microsoft Security Bible


-----Original Message-----
From: full-disclosure-bounces () lists grok org uk [mailto:full-
disclosure-bounces () lists grok org uk] On Behalf Of Gage Bystrom
Sent: Thursday, June 21, 2012 9:25 AM
To: full-disclosure () lists grok org uk
Subject: Re: [Full-disclosure] server security

Well thats a bit of an iffy one. I'd say it IS a security measure, 
albeit one that is solely effective if and only if compounded with 
other measures.

It's unlikely, but you never know, you just might miss out on a 
nasty worm all because you werent running on a  default port one 
day.

On Thu, Jun 21, 2012 at 8:52 AM, Rob <synja () synfulvisions com> 
wrote:
We need to make a distinction between security and obscurity 
here. The only time changing ports actually hardens a service in 
any way is when the port requires elevated rights to bind, 
changing to 1025 for example removes the root requirement. Any 
actual or theoretical vulnerabilities still exist. If somebody is 
looking at your server, they'll find the port without much 
trouble. Alternate ports can remove junk traffic from logs, so 
there is a benefit, if not entirely a security one.

Rob


Sent on the Sprint® Now Network from my BlackBerry®

-----Original Message-----
From: Alex Dolan <dolan.alex () gmail com>
Sender: listbounce () securityfocus com
Date: Thu, 21 Jun 2012 07:44:57
To: Littlefield, Tyler<tyler () tysdomain com>
Cc: <security-basics () securityfocus com>
Subject: Re: server security

One tip I have is to set SSH to a port other than 22, I don't 
need to 
tell anyone how devastating it is if someone did actually get 
access 
to that service. Putting it on some other port reduces your risk

On Thu, Jun 21, 2012 at 1:27 AM, Littlefield, Tyler 
<tyler () tysdomain com> wrote:
Hello:
I have a couple questions. First, I'll explain what I did:
I set up iptables and removed all unwanted services. Iptables 
blocks 
everything, then only opens what it wants. I also use the 
addrtype 
module to limit broadcast and unspec addresses, etc. I also do 
some 
malformed packet work where I just drop everything that looks 
malformed (mainly by the flags).
2) I secured ssh: blocked root logins, set it up so only users 
in the 
sshusers group can connect, and set it only to allow ppk.
3) I installed aid.
4) disabled malformed packets and forwarding/etc in sysctl.
This is a basic web server that runs email, web and a couple 
other things.
It's only running on a linode512, so I don't have the ability 
to set 
up a ton of stuff; I also think that would make things more of 
a 
mess. What else would be recommended?
Also, I'm looking to add something to the web server; sometimes 
I 
notice that there are a lot of requests from people scanning 
for 
common urls like wordpress/phpbb3/etc, what kind of 
preventative measures exist for this?


--
Take care,
Ty
http://tds-solutions.net
The aspen project: a barebones light-weight mud engine:
http://code.google.com/p/aspenmud
He that will not reason is a bigot; he that cannot reason is a 
fool; 
he that dares not reason is a slave.


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-----------------------------------------------------------------
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-- Securing Apache Web Server with thawte Digital Certificate In 
this 
guide we examine the importance of Apache-SSL and who needs an 
SSL certificate.  We look at how SSL works, how it benefits your 
company and how your customers can tell if a site is secure. You 
will find out how to test, purchase, install and use a thawte 
Digital Certificate on your Apache web server. Throughout, best 
practices for set-up are highlighted to help you ensure efficient 
ongoing management of your encryption keys and digital 
certificates.


http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6
be4
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--


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Charter: http://lists.grok.org.uk/full-disclosure-charter.html
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_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

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