PIX unintentional Password Mod Vulnerability

Earlier this week Cisco posted a security advisory regarding a vulnerability in the PIX Firewall. The short of it is that if you store passwords locally and change the configuration there is a chance that the passwords will not be written to flash memory correctly. The outcome is that you will be locked out of your PIX.

The vulnerability affects all PIX running version v7 code [up to and including v7.0(5) and v7.1 up to and including v7.1(2.4)]. If you are running v6 PIX OS you are fine. If you are running an ASA appliance you are running v7 code. This also impacts the v3.1(x or any) train of the Firewall Service Module. If you are using RADIUS or TACACS+ and have configured your PIX for remote authentication (usernames and passwords are defined on the AAA or ACS server) it looks like you are OK also.

The data affected is the passwords stored by either the passwd, username, or enable password commands. This data can be corrupted during a crash or if two users are trying to change the configuration using any management console (CLI, ADSM, PDM) at the same time. The trigger is when you save the password (write memory or equivalent). Apparently this bug writes some other, non random value into flash memory.

So if you were already really smart and using RADIUS or TACACS+ and an ACS server you are OK. Otherwise you may need plan for some network down time and to re-read those the PIX password recovery procedure.

My take on this is that there is very little room for an attacker to exploit this vulnerability. This is the type of problem that causes the Firewall Admin to hurt themselves by corrupting the locally stored password through normal use or maintenance.

Great Port List Reference

I saw this list of TCP and UDP port numbers (from Wikipedia) up on digg this afternoon. Good stuff with good references.

The Surf At Work Page...

Just when I was starting to think that there was nothing good on digg anymore I came across this post about "How to Bypass Firewall Restrictions A.K.A. The Surf At Work Page". This is great stuff. The point of this paper is to explain the use of encrypted tunneling as a means of getting through a Firewall or filtered environment. The paper was originally written in 2002 and last updated in March of 2006 but the principles[ that are put forward here are all correct all still work. All Firewall Admins should read this paper. This is the type of stuff that can get through your Firewalls and filters.

Breaking the Great Firewall of China?

CNet dot com reports that a group of computer experts have broken the Firewalls used by the Chinese government to restrict IP traffic going in and out of the country. Interestingly enough the attack is launched from the outside. To their additional credit the team from the University of Cambridge reported their findings to the Chinese Computer Emergency Response Team.

Good article on FTester

If you haven't looked at "HowtoForge" it's a neat site that's valuable to bookmark and check regularly.

There is a good article up there titled "How To Test Your Linux-Distro Firewall", that gives a brief introduction to FTester. FTest is a security policy enforcement point (think Firewall or IDS) testing tool based on a couple of Perl scripts.

Anybody out there in the world that has been working with the PIX for more than ten years will tell you that this isn't a new idea. The PIX developers originally developed tools to do this (using PIX appliances) about ten years ago. Those tools were used for testing and never left Cisco (or did they?) and were called Hoover and Hooker. Hoover was named after the vacuum company because it was a powerful packet sniffer. Hooker was a packet injector named after the then popular TV cop show character played by William Shatner (after Star Trek and before ST: The Motion Picture). Well, at least that's what we told people when they asked.

ICE References

ICE = Interactive Connectivity Establishment

"The Interactive Connectivity Establishment (ICE) draft, developed by the IETF's MMUSIC working group, provides a framework to unify the various NAT traversal techniques. This enables SIP-based VoIP clients to successful traverse the variety of firewalls that may exist between a remote user and a network."

The above is from a good intro article that appeared in Network World magazine online.

The ICE draft is here.

The ICE wiki page from VoIP-info.org

MS Vista to shrink need for Personal Firewalls and Host Intrusion Prevention?

ZDNet has an article on a new Yankee Group report out today that says Microsoft's new Vista operating system will have improved security capabilities and "significantly shrink" the market for add-on anti spyware and personal firewall software. "Yankee Group expects Vista to significantly shrink the aftermarket for antispyware and desktop firewalls," analyst Andrew Jaquith wrote in the report. I saw Jaquith present at this spring's RSA conference in San Jose, CA and I think he is one of the better analysts covering the computer and network security industry right now.

BlogThis! Firefox extension seems broken...

I don't know if anyone else is seeing this but the BlogThis! extension that I frequently use with Firefox seems broken. If you use it and try to port a entry either as a draft or published to your blog you may see the word "null" in the link field. When I see that BlogThis! isn't working and there is no blog entry.

I wish I had noticed this sooner. I lost some interesting blog entries over the past couple of weeks and I think it is due to this problem.