Optimize Your RSA, Part 2 – Session Tips…

There is a TON of stuff to do at RSA if you are going, and managing all of that can be quite difficult. One of the things that I find difficult to do every year is select the sessions that I am going to. There are a few tools that the conference provides to make this easier.

Let’s take a look at the Session Catalog.

See Who’s Speaking

I have my own personal list of folks who always have great presentations and really pack a lot of punch for me. But, the attendance at the conference is so diverse that my list would certainly not work for everyone. The conference itself measures and metrics speaker performance. You know those forms they hand you as you walk into the session? Turns out that they use that data, and they even share it with you. When using the Session Catalog and the printed materials, you may notice a star next to some of the names. These are the folks who have had the strongest feedback during past conferences.

If this is your first RSA, it may be worth your while to ask folks who have attended in the past and who have similar interests, which speakers stood out to them. If you are a member of the RSA Conference group on Linked In (link), you could even post a question about “Best Session for X”. (Which I have done…)

Preview The Slides

RSA has always made the slides available in advance. Usually this was on media (CD/USB) handed out at the conference. (So, “in advance” was day-before…) But now they are available for most sessions right in the Session Catalog. (Note, you need to be logged in to the site before you visit the page to see these.)

Post Session…

There is a lot of time and energy that goes into being a speaker. Please, help your speaker and the conference, and complete the evaluation forms. And, if a session clicks for you – don’t be shy – meet the speaker. Most of the speakers are presenting because they are committed to the mission and the profession. Participation and feedback are the biggest rewards any speaker can ask for from the audience – don’t hold back.

Hope this is helpful – see you in SFO.

Cheers, Erik

Optimize Your RSA, Part 1 – Expo Management

It is one week until RSA, and now is the time to start planning to make the most of your trip. RSA has one of largest (if not the single largest) vendor Expositions for Information Security. Every year I use this as a one-week refresher course on the products and services that are available. Frequently the class sessions are very valuable to me, in terms of my long term professional development, but  (for my employer) the information I collect on the Expo floor is valuable almost immediately.

Screen Now and Benefit All Year

I am very selective about the vendors with whom, I have  meetings.  Sure, I am missing out on free lunches, but the fact is that I don’t have endless time to meet with people.  As a result I screen, and whenever possible pre-qualify vendors. Most of the time I spend on the RSA Expo floor is spent identifying who I don’t need to meet with, and establishing whom I definitely do want to meet with in the following year.

Understand your Organizations or Clients Needs !

In general you should have a good understanding of your employer or clients… Some key things to understand before heading out to the exposition:

Q: What are the emerging needs of your organization?

What are the areas of concern for your CISO, Risk Mgmt., LOB partners, or other important constituents? In the week or two leading up to RSA, I ping my CISO, key LOB partners, etc. to find out what concerns they have, what vendors have been hounding them for meetings, what alternatives they may need, etc.

Q: What products or services are subject to change?

I feel that, even for our deployed products, it is incumbent on me as a good corporate citizen to make sure those products are still competitive in the market. Information about the competition is especially important during contract renewals. No one negotiates a win-win deal without being fully informed.

Q: Who are you key partners, and what new offerings do they have?

Who are the top vendors whose products you have, and love? Make sure to take the opportunity to visit them, understand emerging features, and make sure that you are getting the most out of your existing investment.

Q: Who will your organization generally buy or not buy from?

Many organizations have firm rules about the types of organizations they will purchase from; know what these are. My experience is that if a product is truly compelling, there is always a way for purchasing to see that and make a deal happen. But, if you sense a weak offering from a company, that is going to be a hard sell to your organization, save time for both you and the vendor – tell them, and move on.

Be There Monday Night

Monday evening at RSA, the Expo opens to Delegates only. The fact that there are fewer people on the expo floor, the booth people are not burned out, and the free food makes this the ideal Expo floor time.

Arrange Key Visits In Advance

As I already mentioned, I try to pre-qualify vendor meetings. There are folks whom I know that I need to be meeting with (established relationships, emerging solutions, emerging risk needs, etc.) and there are a number of folks I know I don’t want to wast time on (lack of compelling product story, people who wasted my time in the past,etc.), but there are also a number of folks in the gray area in-between.

From November on, I start asking folks in the gray area if they are going to have an Expo presence at RSA. If they are, I ask for them to follow-up with me before the show with a booth # and contact name. After I arrive on-site and have the conference book in hand, I add to the list. I avoid setting up specific times, because with everything that happens at the show my schedule is too dynamic.

For each of these “quick meet and greets”, I prep one of my business cards in advance. I have the booth #, contact name, and subject clue on the back of the card. If my contact isn’t at the booth, I leave the card. When you in fact follow-up, you build credibility and relationship, even if there is no service to need synergy at this time.

Be Quick and Targeted

If the printed information, name, etc. on the booth catches my eye, I stop for a quick visit. I try to get the facts quickly, in 3-6 min. The secret is to not be afraid to ask tough questions quickly (but politely), such as:

  • What’s compelling about your offering?
  • Who is your primary competition?
  • Do you have hard data, or a case study you can forward to me?
  • Do you have reference accounts for the use cases that are most important to my organization?
  • What industry analysis (Gartner, Burton, etc.) has been published on this space? Was your product included?

Be Specific About Follow-up

If I have an immediate need, I ask for contact info and I initiate the follow-up before I leave the show. If I am interested in follow-up for a long-term, or next budget cycle, etc. then I usually ask for follow-up later in the year (e.g. Q3/4). Q2 is always a very busy time for me and the people around me, so I try to defer long-term information and knowledge capture until later in the year.

Hope this is helpful – see you in SFO.

Cheers, Erik

Max the Identity & Access Management in Your RSA 2009…

If you are attending the Pre-Conference 1-day Tutorial, Building an Enterprise-Strength Identity & Access Management Architecture, that Dan Houser and I are co-teaching at RSA 2009 please take a moment to drop me a note (using the “Contact Erik” link from the site). This years class is going to be much smaller than last year and should allow for more interaction. As a result, I would like to take the opportunity to maximize the value of that increased interaction, and knowing what topics are top-of-mind for participants in advice will help. 

If you are attending RSA 2009, and plan to be in San Francisco all day on Monday, take a look at the available Pre-Conference 1-day Tutorials (RSA has added a number, and there are many to choose from). There is an additional fee for these Tutorials but based on the feedback from last years class, it was worth it.

Neither Dan nor I work for a vendor or supplier in the space.  We both work for Fortune 500 corporations that have real-world Identity and Access Management challenges (with real-world obstacles). If you are a Linked In member, profile (link) has some endorsements related to this class, as well as other presentations.

Cheers, Erik

AoIS Interviews Michael Rash, Part 3

Michael Rash HeadshotThe Art of Information Security continues our interview with Michael Rash, Network Security expert and the driving force behind several open source security tools including PSADFWSnort, and FWKnop.

In Part 2 of the interview Michael discussed how network threats, and network counter measures have been evolving. He also touched on the development of his book. Here goes the final installment in this series…

Erik: What would be your recommendations for folks who are adopting Linux (either enthusiasts or corporations) in terms of properly protecting their hosts and networks from network attacks?

Michael: I think that deploying host and network firewalls is a great first step here, and iptables functions admirably. Many people in corporate environments are concerned about the questions of performance, manageability, scalability, and support, and iptables together with some third party software have decent answers to these concerns. For example, the fwbuilder project provides good graphical support for the display and manipulation of iptables policies, and large Linux distributions such as Red Hat and SuSE offer commercial support.

Beyond having proper firewalls deployed, intrusion detection systems are a critical piece to point the way to attempted (and sometimes successful) compromises. Also, strong security mechanisms such as SELinux can provide a powerful barrier to attempted malicious usages of hosts. Finally, patch early and patch often.

Erik:  Do you have any tool or reference recommendations for debugging IP tables firewalls?

Michael: For debugging iptables policies and maintaining tight controls on the type of packets that are allowed to traverse those policies, one of the best techniques is to use tcpdump either on the end points or on the firewall itself (and these may be the same system) and watch how network traffic is allowed to progress. For example, a SYN packet to a port that is filtered will not respond either with a SYN/ACK or a RST, and seeing this behavior with tcpdump is quite easy. At the same time, understanding where in an iptables policy packets are getting dropped (or otherwise messed with) is usually made clear by watching how packet and byte counters are incremented on particular iptables rules. Use ‘iptables -v -n -L’ for this, and couple this with the ‘watch’ command to see how things change. Beyond this, if you have a kernel compiled with support for the iptables TRACE target, then you can use an iptables TRACE rule that causes all packets hitting this rule to be logged. Lastly, for really advanced debugging of iptables code itself, the nfsim project provides a simulator for running Netfilter code within userspace (and hence the ability to test code before running it within the kernel itself where a bug can have dire consequences). The nfsim project can be found here:

http://ozlabs.org/~jk/projects/nfsim/

Erik: So, you obviously are deeply connected to all things Network IDS/IPS. What kinds of trends have you seen in 2008? Were there any new attack styles that surprised you? Do you have any ideas about what 2009 may hold?

Michael: Well, 2008 will certainly go down in history as the year that people were forced to really pay attention to DNS by the Kaminsky attack. One thing Dan did really well is make it clear just how important DNS is for literally everything on the Internet, and how a flaw there has implications that are difficult to over estimate. Online banking, acquiring SSL certificates, SMTP, “forgot my password links”, and countless other infrastructures depend on DNS information being correct. But, then there were also serious issues in 2008 with BGP and with SSL, so if there was any trend in 2008 I would say that it was the year of security flaws in big Internet infrastructures. In 2009, it will be interesting to see whether this trend remains true for as-yet undiscovered vulnerabilities in other important systems.

Erik: Has your support for open source helped you professionally?

Michael: Absolutely. My current position as a Security Architect on the Dragon IDS/IPS developed by Enterasys Networks is a role that my open source work helped me to acquire. Many forward looking innovations are created by the open source community, and understanding this community helps to guide many companies and the products they develop. Companies are recognizing the power of open source software more and more, and this translates to better professional positions for open source developers and technology enthusiasts.

Many Thanks to Michael !

Thanks a ton for the time and energy you put into this, the first of what I hope will be many, interviews with notables from around the Information Security community.

Thanks, Erik

Even more SSH – Great Article on /dev/random

Quick update to Part 2 of the AoIS Secure Your Linux Host Series on SSH.

I noticed a great article today on  Xavier Mertens/dev/random blog (which by the way has several great posts that have caught my eye…), on SSH tunneling -> “Keep an Eye on SSH Forwarding“.

In addition to providing a solid introudction to SSH Port Forwarding Xavier also discusses:

  • Using SSH as a SOCKS Proxy via the SSH Server
  • Logging port forwarding
  • Restricting  ports that can be forwarded

Check it out.

Cheers, Erik

AoIS Interviews Michael Rash, Part 2

Michael Rash Headshot

The Art of Information Security continues our interview with Michael Rash, Network Security expert and the driving force behind several open source security tools including PSAD, FWSnort, and FWKnop.

In Part 1 of the interview Michael discussed how he came to be involved in Network Security and Intrusion Detection system design. Here in Part 2 we get a little deeper into Michael’s philosophy on Network Intrusion Protection and discuss more open source tools that he is involved with the develop and support of.

Erik: How do you see network based attacks changing ?

 Michael: Over time, I think network based attacks will continue to be more automated and therefore accessible and deployable by more people. When it comes to educating oneself on the details of network insecurity, excellent projects such as Metasploit, Nessus, and Nmap point the way – and this is essential also for people trying to defend networks too. We will see more attacks delivered over IPv6, and we will see ever more clever ways to exploit the natural tendency of people to trust data in ways they shouldn’t. For me as a person trying to protect networks, the later is the most worrisome. A good example of a new and clever attack is “in-session phishing” as described here (Arstechnica link).

Erik: The firewalls that I run are utilized as host based protection. As you see network security becoming increasingly important, do you see the firewall “concept” become a hybrid of network protection layered over host based network controls?

Michael: With good firewall implementations (such as iptables) that do not place undue burdens on network processing that takes place on hosts, I do believe that firewalls will be viewed more and more as an essential protection mechanism for the host. The network perimeter will also continue to be an important deployment point for large firewalls to enforce global policy, but limiting the damage a successful exploit against an internal system is a problem that such an external firewall is not well-suited to address. Having a hardened network security stance on each host can provide an important benefit in this area. Further, as firewalls offer more application layer processing features, hosts can deploy customized policies that define sets of application layer data (derived from Snort rules) that are unfit for communicating with local sockets.

There are challenges though regarding managing all of those host-level firewall policies, and this is where some patience and scripting ability can play a roll.

Erik: And then came FWSnort? What were the principles that drove the development of FWSnort ?

Michael: The fwsnort project was inspired originally by the snort2iptables script written by William Stearns. This was back in the Linux 2.4 days when the string match extension was still distributed within the patch-o-matic system from the Netfilter project. Being interested in intrusion detection and firewalls at the same time, it was a goal of mine to see how far iptables could be taken in the direction of detecting (and blocking) malicious traffic. The snort IDS had a well-developed signature language, and at that time the signatures were still free and released under the GPL. So, it was natural to try and extend the snort2iptables code, and fwsnort was created.

The main goal of fwsnort is to use facilities provided by iptables to recast Snort signature sets within iptables policies. A clean translation is not always possible particularly with complex Snort signatures that use regular expression matching (because no regex engine is available to the iptables code running in the kernel), but many Snort signatures can faithfully be translated.

 Erik: Was your vision that PSAD and fwsnort teamed up as host IDS dynamic duo, or more as services that strengthen network firewalls?

Michael: Ideally I would say both here. The difference between the two types of deployments is negligible from psad and fwsnort’s perspectives – both can be deployed just as effectively against the iptables INPUT chain (for packets directed at the local system) as the FORWARD chain (for packets directed through a network firewall). The effect of not deploying host firewalls is that the outside of the network may be protected by a crunchy shell, but the inside is a chewy center. If any system can be compromised internally on such a network, an attacker is presented with few barriers to additional actions once the perimeter is breached.

 Erik: But wait – there’s more ! You are also the driving force behind FWKnop !

Michael: Thanks for mentioning fwknop. This project has received a large percentage of my attention in the last year or so. It was started originally in 2004 as the first port knocking system that added passive OS fingerprinting as an authentication parameter, but in 2005 Single Packet Authorization was added. SPA solves many of the protocol limitations that are built into port knocking (ease of replay attacks, lack of decent data transmission, and difficulty of scaling to many users), and takes the idea of “default-drop” to a new level. That is, a service such as SSH is itself made completely inaccessible before the lightweight SPA packet is passively sniffed and the firewall is reconfigured to allow access only if the SPA packet is valid. This essentially combines techniques from the IDS world (passive packet sniffing) with techniques from the authentication and authorization world (encryption and the like).

Erik: And how did the book come to be ?

Michael: I have generally tried to capture my thoughts on computer security by writing them down. In 2001 I started writing articles, and wrote a few for the Linux Journal after working with Jay Beale on the Bastille Linux project. From there, I joined Jay with writing material for Snort books for Syngress. My open source development interest has always remained in IDS and firewall technologies, so I eventually decided to write a book about the two together. The result was the No Starch book. Let me just mention here that if any of your readers is interested in writing a book, I can wholeheartedly recommend No Starch as an absolutely fantastic publisher to work with.

Stay Tuned for Part 3

Part 3 of this series is coming soon, with more discussion about network security as well as the impact that contributing to open source tools has had on Michael professional opportunities.

Cheers, Erik

 

Secure Your Linux Host – Part 3: Why A Host Firewall ?

This post is going to focus on building and applying a Host Firewall using the IPTables functionality that is built into Linux. (If you are already lost, try googling “securing linux with IPTables”, and check out the resources section below.)

Please note: This Secure Your Linux Host series is very hands-on.  The tools and tips that will enable you to use a Host Firewall are coming, but let’s lay the foundation for using them first…

What is a Host Firewall?

When the concept of Firewall is mentioned, the most common meaning that comes to mind is a network services control between networks. Over 90% of the information that you can find on Firewalls is targeted at people who want to protect systems on one network (such as their corporate or home LAN) from systems on another network (generally the internet), while permitting a list of known services to be accessed by one network from the other. There are in fact several effective strategies for using Network Firewalls as boundaries between networks, or network segments.  For a detailed introduction (or tune up) on this subject, please refer to the NIST document in the resources section below, or click here for a great SANS introduction.

A Host Firewall is different in that it exists to protect and control access to a single system from all others. Common scenarios a Host Firewall is well suited to address:

  • Host is in direct contact with the Internet (or other hostile network)
  • Host is located in a DMZ
  • Host cannot trust systems on its network segment
  • Host has high control expectations due to legal, regulatory, audit, or risk requirements

If you have servers that are hosted in a data center or directly connected to a broadband/DSL connection and, as a result, are in direct contact with the internet, then I highly recommend configuring a Host Firewall. Systems that are in this situation will be attacked from other systems all over the globe all of the time. There are so many attackers who are running probing scans across the entire network space of the Internet that you will get scanned. The recent log information that I supplied on http scans and ssh password attempts is an example of how any host (no matter how insignificant) will be regularly attacked.

dmz_conceptual OK –  so what if the host is behind a firewall in a DMZ with other hosts (such as the www and SMTP, hosts in this illustration)? Most DMZ networks do not provide protection against attacks from other “peer” hosts in the DMZ. The problem that this presents is that, in the event that one host in the DMZ becomes exploited, then it can be used to probe and attack all of the hosts in the DMZ. Even worse, if a single host in the DMZ falls prey to a Worm or other self-propagating threat, then all similar hosts in the DMZ can be rapidly infected.

The “Host cannot trust systems on its network segment” argument for a Host Firewall is almost identical to the DMZ argument. Why provide access to services on the box to systems that do not need them?

The last point is about high-risk or highly-regulated systems. The rules on a Host Firewall are much simpler to review and understand (but perhaps not manage) than the rule set on a network boundary Firewall. This can have two major  advantages. First, it can make it much easier to provide complete and frequent reviews of the Firewall rule set. Second, it can remove confusion, limit scope, and simplify formal audits of the network access that the given Host has.

Isn’t Linux Secure by Default?

Many Linux distributions and commercial operating systems advertise that they ship in a “fail safe” or at least “start safe” mode; let’s assume that to be the case. When you install any operating system, the first thing you do is start installing software and applications. With each application that you install, you may be exposing services to the network.

With a Host Firewall, you will know precisely what services you are and are not exposing. As you know from Part 1, I run a Mail Transfer Agent so that email to root, events, etc. is in fact delivered to an email account I actually use. Running a Host Firewall dramatically raises my confidence that I am not a SPAM relay – sure, I think I configured the MTA properly… But with the Host Firewall I know that only services on my host (via 127.0.0.1) can send email. Running a LAMP server provides a very similar situation. With the Host Firewall in place, I know that MySQL isn’t accessible on its native ports to the world.

So, What is the Downside?

The reason that more systems are not running a Host Firewall is a lack of management tools. If you have a small number of hosts that you are administrating, then adding and managing a Host Firewall is not much work at all. But, if you have a hundred servers with a mix of operating systems, split into several data centers, suddenly managing Host Firewalls is not only a nightmare but may be causing more operational risk than is acceptable.

Every modern operating system (Linux, Unix-*, Windows, System/Z, openBSD, etc.) comes with a built in Host Firewall capability. What is needed is tooling that enables both centralized management and harmonization with network boundary Firewalls. (Unfortunately, I won’t be able to provide that in this series!)  The vendors with the best management of the network boundary Firewalls tend to be the manufacturers of those Firewalls, and they would be the most logical group to expand their existing management capabilities into the Host Firewall space. But, I do not think that anyone has developed a revenue model to justify that as worth the investment. (Hope springs eternal!)

What’s Next?

In the next installment, I am going to walk through the actual artofinfosec.com Firewall. (No B.S. “Security Through Obscurity” here!) And then in the following segment, I am going to discuss tools for monitoring and adding countermeasures to the Host Firewall.

Resources

  • Securing Linux Systems With Host-Based Firewalls Implemented With Linux iptables (htmlpdf)

This is a great introduction to building a Host Firewall. (The html site version seems like a paraphrase of the Sun Blueprint document pdf.) It is a resource that I return to time and again. The firewall example provided here includes full egress control, and the article walks the reader through the firewall step-by-step. The description is for a very controlled Host Firewall, so controlled that I in fact found myself moving to a simpler implementation.

  • NIST: Guidelines on Firewalls and Firewall Policy (pdf)

The NIST documentation (as usual) provides a great 360-degree medium-depth introduction to the topic. If you currently, or are about to, manage firewalls as part of your network security function, then read this guide!

Cheers, Erik

AoIS Interviews Michael Rash, Part 1

Michael Rash Headshot

The Art of Information Security has the great pleasure of interviewing Michael Rash. Michael holds a Master’s Degree in applied mathematics with a concentration in computer security from the University of Maryland.  He is the founder of cipherdyne.org, a website dedicated to open source security software for Linux systems, and works professionally as a Security Architect on the Dragon IDS/IPS for Enterasys Networks. He also is the author of “Linux Firewalls: Attack Detection and Response with  iptables, psad, and fwsnort”  (Sample chapter and more information here) published by No Starch Press.

When I started the Art of Information Security blog, I felt that it was important to appropriately lock down the host. It would be an unfortunate irony to have the server hosting a security blog “owned” by some script kiddy. So, of course AoIS runs a firewall. I had been using iptables firewalls on Linux for a while, and there were a few things that I felt were lacking from the set-ups that I had in the past. One was the ability to understand that the firewall is working. A solid firewall generates logs – but what do you do with those? And, what do they tell you? Second, I knew that I should be able to detect certain types of automated attacks and block those IPs. There are so many improperly configured hosts to attack that a few simple countermeasures go a long way. Third, I have also been very interested in running host IDS/IPS, but all the requirements to run Snort for a single host seemed a bit too much. Alas, I ran to cipherdyne.org and the great tools sponsored (and authored) by Michael.

Erik: So, Michael, Network Security is obviously more than just a job for you. How did you come to be involved so deeply in Network Security and Intrusion Countermeasures?

Michael: During the late 1990’s I was introduced to intrusion detection on a large ISP’s network, and that experience coupled with learning networking protocols sparked a deep and abiding interest in network security. This interest eventually led me to systems programming on Linux, and to the internals of systems that need to be protected. The constant game of cat and mouse played by attackers and defenders in the network security world never ceases to provide new directions for security research, and thanks to the open source development model, many of the techniques to defend systems can be investigated and contributed to by anyone.

Erik:  So when did you get the idea for PSAD?

Michael: In 1999 I started working with Jay Beale on the Bastille Linux project. At the time, both portsentry and Snort were around and were designed to detect network attacks (with the former only focused on port scans). Because Bastille was designed to harden the security stance of the host, a strong iptables policy was built in by Peter Watkins. With the strategy implemented by portsentry of listening on sockets in order to detect port scans (see the this link for why this is less than ideal from many perspectives), we needed a way to detect port scans in a manner compatible with Bastille’s iptables policy. The result was a portion of Bastille initially called “Bastille-NIDS”, but I eventually split it off as a dedicated project, and called it “PSAD”. An option would also have been to just write a configuration utility for Snort, but there would still have been a void since no tool really analyzed iptables log messages for suspicious activity. I made it my goal to try and fill this void mostly because the data source provided by iptables log is quite rich and has a lot to say.

Erik:  On your website you identify three principles around which PSAD was developed. Why are these important? How does PSAD accomplish them?

  1. Good network security starts with a properly configured firewall
  2. A significant amount of intrusion detection data can be gleaned from firewalls logs
  3. Suspicious traffic should not be detected at the expense of trying to also block such traffic

Michael: Network security is more relevant for more people today than at any other point in Internet history. Important infrastructure is increasingly being put online (such as online banking access), and the threats are evolving to compromise this infrastructure. The default stance of many operating systems is to listen on several services to make things easier for users, and while many OS’s (particularly mainstream Linux distributions) offer to configure firewall policies, many users elect not to go through with this step. Sometimes people are too busy to maintain a properly configured firewall, or they reason that the local border firewall is sufficient. Firewalls should always be configured in a default-drop stance in order to provide an additional layer of protection for any vulnerable services that may be listening. For Linux systems, psad helps to verify that the local iptables policy is configured in this manner.

Firewall logs are also an important area to pay some attention. Although firewall logs cannot replace the full packet capture and logging capability of many intrusion detection systems, they can still be a valuable source of data to highlight efforts to break into systems. With a logging format that is as complete as provided by the iptables logging infrastructure, it is possible to detect and differentiate most types of nmap scans, passively fingerprint remote operating systems, detect probes for back doors, and more. The process of parsing iptables logs to look for these kinds of activities is automated by psad.

Finally, just detecting malicious traffic will always play second fiddle to an effective mechanism for also blocking such traffic. The iptables firewall is a well-tested piece of code that runs inline to the packet data path. Hence, it is a strong weapon to block suspicious traffic with a default drop stance before such traffic is allowed to target internal systems. By using the iptables string match extension, iptables blocking actions can even be tied to the inspection of application layer data.

Stay Tuned for Part 2

Part 2 of this series is coming soon, with more discussion about network security and open source security tools. More information is available on PSAD at http://www.cipherdyne.com/psad/. (Oh, and PSAD will be featured in an upcoming installment of the AoIS Secure Your Linux Host series !)

Cheers, Erik

More SSH Anyone ?

Two Quick updates to Part 2 of the AoIS Secure Your Linux Host Series on SSH.

Interesting Series by ISS X-Force on SSH

Just this morning I ran across a three part series on SSH published last year in IBM’s Internet Security Systems X-Force Threat Insight in the following issues:

X-Force expresses a slightly different set of concerns, and solutions. One topic that I did not touch on was the use of ssh agents for the management of sessions. Part 3 (June) is almost entirely focused on that.

Logwatch Samples

One of the great things about the script kiddies is they are keep testing your security for you ! 😉 Below is a mash-up and edit-down of the last few days of ssh related itms from my logwatch logs. Logwatch really has become one of my favorite tools. I don’t have tons of attacks on my servers, but there is always enough activity in the logs to let me know that the controls and countermeasures are up and running. After installing fail2ban, I always have some activity in 24 hour period of time. 

And a tip for the paranoid – if you have Failed logins and Illegal users but no fail2ban activity – then fail2ban has stopped running (or worse…).

——————— fail2ban-messages Begin ————————
Banned services with Fail2Ban:
Bans:Unbans  
ssh: [ 6:6 ]  
ssh: [ 4:7 ]  
ssh: [ 6:5 ]
ssh: [ 5:3 ]
———————- fail2ban-messages End ————————-

——————— SSHD Begin ————————
Failed logins from:
75.xxx.109.82 (75-xxx-109-82-Indianapolis.hfc.comcastbusiness.net): 1 time
79.xxx.248.27 (host27-xxx-static.38-79-b.business.telecomitalia.it): 1 time
200.xxx.209.156 (dedint-200-xx-209-156.mexdf.axtel.net): 3 times
59.xxx.92.26: 6 times
88.xxx.16.23 (…): 7 times
119.xxx.154.57: 6 times
203.xxx.198.3 (…): 6 times

Illegal users from:
60.xxx.249.90 (…): 3 times
75.xxx.109.82 (…): 3 times
79.xxx.248.27 (…): 3 times
200.xxx.209.156 (…): 2 times
202.xxx.28.244 (…): 3 times
85.xxx.133.177: 4 times
193.xxx.161.136: 4 times
———————- SSHD End ————————-

Cheers, Erik

Lie Detector Libel

I noticed a posting on Slashdot (link) this morning regarding a gag order on an article that was to be published in a peer reviewed scientific journal but has been suppressed. The article was critical of lie detector technology, and evidently provided information debunking it.

More information is available her:  Stockholm University article.

The thing I find most interesting about this is that the US Supreme Cort has already determined that Lie Detectors are unreliable. From Wikipedia article on the polygraph:

In the 1998 Supreme Court case, United States v. Scheffer, the majority stated that “There is simply no consensus that polygraph evidence is reliable” and “Unlike other expert witnesses who testify about factual matters outside the jurors’ knowledge, such as the analysis of fingerprints, ballistics, or DNA found at a crime scene, a polygraph expert can supply the jury only with another opinion…”.

One of the things I find most interesting about the challenge of “testing” lie detectors is that no testing, such as the tests performed my Emily Rosa to debunk Therapeutic Touch, have ever been offered with can objectivity demonstrate the that they even work.

Cheers, Erik