Archive

Archive for the ‘security’ Category

Public Key Cryptography: Diffie-Hellman Key Exchange

March 23rd, 2012 No comments

Categories: security

Avi Rubin – All Your Devices Can Be Hacked

March 21st, 2012 No comments

Categories: security

Pulledpork

May 10th, 2010 No comments

If you are using Snort as IDS you might want to take a look at pulledpork for updating an managing rules.

Categories: networking, security, tools

nmap survey

April 8th, 2010 No comments

There is a survey about nmap.

You can also vote for your favorite security tools and you can even win something.

Categories: security, tools

Troubleshooting

April 6th, 2010 No comments

Sometime ago I was asked to investigate why a certain script was running so slow. The script used fwm logexport to convert a Checkpoint log file to an ASCII file.

While the script was running, network access to the server was realy slow. Having access to tcpdump or Wireshark would have shown what was happening. Unfortunately Windows doesn’t ship with such essential tools in the default install.

Reading the manual made it possible for an educated guess. There are two parameters -n and -p to disable DNS and Port resolution while converting the logfile. And guess what: Instead of a couple of hours the script only needed some minutes to finish. (The log file was about 2.000.000 lines long.

So here is the syntax used now:


fwm logexport -n -p -n -i %fwdir%\log\input -o output

Survey of IPv6 Availability on Commercial Firewalls

April 3rd, 2010 No comments

Until May 1st you can participate is a survey on IPv6 support in commercial firewalls from ICANN.

I can’t wait to see the results.

Categories: ipv6, networking, security

The other day…

April 2nd, 2010 No comments

I made a joke that “cisco” is the default password on most Cisco systems because they use it in theire documentation and training material. A colleague wouldn’t believe me. Than he asked me if I could check something on a customers Cisco router when he gets me a user name and password.

Guess what. cisco worked for login and enable.

For those of you who don’t know Cisco: Normally there is no default password. You can only login remotely when you configure remote access via ssh / telnet and a password. Until then you only have access to a serial console.

Categories: Cisco, networking, security, WTF

ACL management

March 18th, 2010 No comments

It’s always a problem to keep all your ACLs in a network coherent. Recently I was made aware of a small tool form google which makes managing ACLs on Cisco, Juniper and Linux much easier to handle.

Take a look at Capirca.

Some features, like IPv6 ACL support for Cisco is still missing, but it looks quite promising.

Telnet?

October 29th, 2009 No comments

I recently reviewed a Cisco router configuration. Access via ssh was disabled and only telnet was allowed from some host. Ok, IOS only supports key authentication starting with IOS 15 but I thing that using an encrypted channel to configure and troubleshoot a router is better than clear text. And ssh is available in the standard image for quite some time.

Categories: Cisco, networking, security

Strange Question…

August 26th, 2009 No comments

I’ve given my usual presentation on IPv6 last Saturday @FrOSCon and there was one question nobody asked before:

“When will IPv6 be as secure as IPv4?”

IPv4? Secure? Did anyone bother to read the latest CISCO security advisory’s? From my point of view IPv6 is as secure as IPv4, maybe even more if you keep in mind that all problems with NAT are gone. Sure there will be bugs in the implementation but there are still bugs in some IPv4 implementations. Most of the problems are in applications using upper level protocols, especially HTTP apps written in PHP.

Categories: ipv6, networking, security