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-   -   Nmap-Os Finger Printing (https://www.linuxquestions.org/questions/linux-security-4/nmap-os-finger-printing-307393/)

XaViaR 03-29-2005 09:59 AM

Nmap-Os Finger Printing
 
hello,

I am trying to hide my os finger print. I know that this is hard, and not the only way you need to "protect" your os. I also do patching, hardening scripts, stop unneded services, upon other things.

As of recectly, I have been trying to secure my Suse 9.1 Linux machine from my nmap results. The nmap results had three conerning results.
1. It should the uptime. (i fixed this through sysctl)
2. My system could be pinged. (i also fixed this throuh sysctl)
3. The nmap results showed my os. (this is what i am trying to stop)

I have been reading articles about how to stop or obscure the results.
1. I can use ippersonality.
Does this work well under the 2.6.52 kernel? I know the code is under development. What do you think?

2. I can drop ALL unsolicited packets?
I am fairly new to linux. So I was wondering how is this done? Currently I am using yast_suse_firewall2.

Thanks in advance for your help! :-)

frgtn 03-29-2005 10:48 AM

A few years ago i had found a tool, called "fingerprint fucker" (sorry, but it's the name). Never actually used it, but it should have some kind of a readme. Try googling for it as i don't remember the adress.

XaViaR 03-30-2005 10:07 AM

any other ideas?

Krugger 03-30-2005 06:08 PM

patch with grsecurity and you get a randomized response. Although it doesn't change that much there are some kernel patches that did this. I saw nmap identifying a linux box as windows with one of these patches, but I don't recall the name of the patch.

http://www.grsecurity.net/

houler 04-01-2005 11:24 PM

Re: Nmap-Os Finger Printing
 
Quote:

Originally posted by XaViaR
...

As of recectly, I have been trying to secure my Suse 9.1 Linux machine from my nmap results. The nmap results had three conerning results.
1. It should the uptime. (i fixed this through sysctl)
2. My system could be pinged. (i also fixed this throuh sysctl)
...

Nice! care to share how you did it?

XaViaR 04-02-2005 09:02 AM

i made a file called...

/etc/sysctl.conf.

i added the following lines....

#turn off the tcp_timestamp (uptime)
net.ipv4.tcp_timestamps=0

#turn off ping
net.ipv4.icmp_echo_ignore_all=1



that is it!

I hope this helps.

houler 04-02-2005 10:27 AM

cool. Thanks for replying. :cool:


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