What is OpenDNS and What can it do for me?


OpenDNS is a Domain Name System (DNS) service that you can use as an alternative to the DNS system that your internet service provider offers.

For those not familiar with DNS , it can be summarized as the service on the internet that takes the website address or server name you type in and translates that into something your computer and systems on the Internet can use to find your website or server.

So why use OpenDNS?

Whether your know it or not, when you are hooked up to your cable modem or DSL line, your internet service provider (ISP) automatically tells your systems which “DNS” servers they should use. Is this a bad thing? No, but using OpenDNS can give you much more functionality than than the DNS servers your ISP gives you to use.


What does OpenDNS do that my ISP’s DNS servers don’t do?

The OpenDNS servers offer many services that regular DNS servers do not.  Below is a list of the services that OpenDNS can provide.

  • Phishing & Botnet Protction
  • SmartCache
  • Web Content Filtering
  • Constant Updates
  • Whitelist/Blacklist Mode
  • Detailed Statistics
  • Typo Correction
  • Shortcuts

Isn’t there sofware I could install that does this?

Yes. But the problem with software is that it only works on each machine after you install it. The software must also be updated from time to time. It is also possible to bypass web filtering software installed on computers if you really want to. By using DNS servers to provide this function, you don’t have to install or maintain any software on your computers, it doesn’t slow anything down, and it is much easier to maintain. Once you are using OpenDNS it is maintenance free.

Also, does your website filtering software run on your iphone or samsung tablet or MAC or Linux machine? Probably not. But OpenDNS can provide the functionality at your home without having to install anything.


So how do I use OpenDNS?

Go to and sign up for an account. Once you do you can find information on how to configure your computers to start using OpenDNS.  OpenDNS is an easy way to help restrict access to websites that are inappropriate for children and protect your computers from bad websites overall. The alternatives require more work or more cost, and don’t typically provide any more features.


Unauthenticated vs Authenticated Vulnerability Scans and Testing

What is the difference between “Authenticated” and  “Unauthenticated” Scanning or Testing?


Unauthenticated =  No usernames and passwords are used in the scanning or testing.

  • This means if your website allows users to create a shopping cart tied to a user, the testing will not attempt to use a username and password to replicate a user’s usage of that shopping cart.
  • This type of testing is typically less intense because it will only be able to find basic configuration issues or input and output validation type errors that don’t include the code base that handles user transactions like shopping carts.
  • Unauthenticated scanning and testing may attempt username and password combinations to attempt to logon to your system, but they typically only check to see if the credential is valid, and will not use it to login to the system to perform further testing.

Authenticated = The scanning or testing is able to use usernames and passwords to simulate a user being on that system or website.

  • Authenticated testing can be much more intense and have the possibility of causing impact to your website or system.
  • Authenticated testing will usually find more vulnerabilities than unauthenticated testing if a vulnerability scanner is given credentials into a system. This is simply due to a scanner’s ability to see more of the system due to being able to get “inside” the system and validate issues instead of the guesses that a scanner or tester must make without authentication.
  • Authenticated testing has much better code coverage on applications since it can simulate much more of the user based functionality like transactions.
  • Some authenticated and un authenticated scans can simulate “brute-force” style attacks, which could cause account lockouts depending on your system configurations.

Why should I care?

  • Authenticated testing is much more thorough and is often able to find more issues than unauthenticated. However, it is also more likely to cause issues on a system or application.
  • Since authenticated testing will often find more, you will spend more time parsing through data and trying to determine which findings are higher risk.
  • Finally, unauthenticated testing alone will not simulate targeted or successful attacks on your application or system, and is therefore unable to find a wide range of possible issues.

Ask yourself these questions to decide what kind of testing or scanning you need.

  • What is the purpose of the scan or test? (Specific compliance requirement??)
  • Do my scanning or testing requirements give preference to authenticated or unauthenticated testing?
  • Do I want to simulate what a user on the system could do? (Go with Authenticated)
  • Do I want to start at the highest risk findings that any scanner or user on my network could find? (Go with unauthenticated)
  • Is this the first time the system or network has ever been scanned or tested? (Go with unauthenticated unless you have other requirements.

So what should my approach be?

Using a risk based approach, you could start with unauthenticated scanning and testing because it will typically find the highest risk and most significant issues. Once you have the unauthenticated findings, you can gradually start authenticated testing once you have a good comfort level that it will not impact systems.

Note*** In large environments you may need to be wary of old printers and devices that may have old network stacks. You will typically only see scan issues on legacy network appliances or devices like old network printers.

PCI Penetration Testing

The Payment Card Industry Data Security Standard requirement 11.3  requires that you perform annual external and internal penetration testing that also includes application testing. Below is a guide on how to handle your testing requirements.

*Disclaimer* Every company and situation is different when it comes to PCI. Always communicate with QSA(s) when planning your testing to ensure that you are meeting all the needed requirements.

Scope –

First you have to decide how you are going to define the scope of what is going to be tested. This includes which networks and applications are to be tested. This scoping process may also include deciding what type of testing will be done such as black-box, white-box, goal based, etc… The PCI-DSS leaves this scope determination up to your company.

  • Be completely transparent on the possible ingress and egress points to your PCI data.
  • The goal is to find out your weak points, not to stump the penetration testers.
  • If you are limited by cost on the number of IP’s that can be penetration tested, then I would ask if the testers could start with the 3 sets of information below and come up with their own limited list of IP’s to test, or do this yourself.

I’ll refer to these 3 sets of information below as the 3 core vulnerability information sources.

  1. Full vulnerability scan (unauthenticated or authenticated)
  2. Firewall rule exports
  3. Network diagrams

External Network –

  • Start with the 3 core vulnerability information sources to determine your testing targets.
  • Perform specific application testing on your sites that handle any type of PCI data.

Once your sites start coming up clean regularly, you should consider moving to authenticated testing if you aren’t already doing that type of testing.

Internal Network –

  • Start with the 3 core vulnerability information sources to determine your testing targets.
  • Hand over information on any specific solutions and dataflows that handle PCI data.
  • Use those firewall rule exports so you don’t forget to test the servers that have connectivity into your PCI data network if it is separated from your other networks.


  • Focus on any applications that handle PCI data.
  • Do not limit testing to only PCI data handling applications. You should also do penetration testing on system management applications, software distribution applications etc..
  • The best application penetration test is to do a source code review in coordination with functional testing.


Once you have all the results back from the testing your real work begins.

  • Take a risk based approach to determine what needs remediation.
  • There is flexibility in your remediation under the PCI-DSS, so chose a logical and consistent manner in how you choose to remediate issues.

As always, it would be good to get your approach approved by a QSA if possible.

Final Thoughts…

The goal of penetration testing is to simulate a malicious (or curious) hacker’s attempt to access sensitive data or systems. You should view this as an opportunity to improve security and not a threat.

Be transparent, use good testers, and try to change your testers every couple of years.  Penetration testing is often more of an art than a science, so different people will often find different holes.

Vulnerability Management – Continuous vs Batch

Reasons why a “Continuous Vulnerability Assessment and Remediation” process is better than a quarterly scan or “batch” process.

Continuous Security

“Continuous Compliance” is a fairly hot security topic. The word “continuous” has almost reached a buzzword status when it comes to information security topics like vulnerability scanning and application security.  So I decided to look around at some of the products and pages on the Internet that cover this topic. I found some explanations of what continuous compliance is and products that supposedly do it. However I didn’t find anything that went in depth to explain why continuous compliance is better in regards to security vulnerability discovery and remediation.

I felt that I knew why it was better, but I always like to do some research to validate my assumptions. I hope you do also.  Below I use “Continuous Vulnerability Management” as a synonym with “Continuous Compliance and Continuous Configuration Management.

Where Is The Answer?

I didn’t find the explanations and answers I was looking for in vulnerability management topic pages or security focused blogs. I remembered from my undergrad and MBA operations management classes that continuous is typically better than batch, so I figured business and operations management topics would hold the hard answers I wanted to find.

BINGO!  I found the answers on Operations Management and Real-Time Business Intelligence type forums and websites.

I’ll summarize my findings below.

Benefits of Continuous vs Batch

  • Once you start a continuous process, you can run it constantly. There is no need for setup and tear-down times. This removes the wasted effort of having to regularly spend time ramping up discovery and remediation efforts, and spinning those efforts down, just start them over again.
  • Continuous allows you to use less resources to complete work because the work is spread out as needed into smaller more manageable chunks. Instead of delivering a bunch of findings every few months, the findings are delivered or “pushed” immediately as they are found. Theoretically, this may allow vulnerability owners to just “work in” remediation work with other support tasks instead of having to focus on large lists of findings.
  • Continuous vulnerability management should be more scalable. Due to continuous vulnerability management requiring less overall resources at any one point, it should be easier to get more overall work done by allowing a person to break out a large amount of work into manageable chunks or more easily add resources to remediation efforts.
  • Continuous should cause less disruption to regular business operations and support. In order to support continuous vulnerability management, it must become a part of your normal operations and support. I can tell you from experience that when you deliver a large list of findings once every few months, the vulnerability owners act like it is a surprise each time for a few years, or at least hope you will forget about them.
  • Continuous vulnerability management should create less risk for business impacting issues due to configuration changes. This lowering of risk is due to vulnerability remediation work being completed in smaller chunks of work instead of trying to cram tens or hundreds of configuration changes or patches through in a short amount of time.  Experience shows this “cramming”  usually results from a large “batch” style list of vulnerabilities.
  • Similar to the reasoning above, continuous vulnerability management should have fewer errors than batch processing because remediation work is done in smaller chunks. The smaller work units should allow for more focus on each individual work unit, instead of the feeling of being rushed to get a large batch of work completed in a short amount of time.
  • Root Cause Determination should improve. In continuous vulnerability management you have much shorter amount of time between when a vulnerability is created and when it is found. It is simply easier to remember (or to track down) what someone did yesterday than what was done weeks or months ago.

Bottom Line? Compliance & Security Improves

  • All of the above reasons contribute to a cumulative improvement in the efficiency of a continuous process over a batch process in regards to vulnerability scanning and remediation. The cumulative negative effect of the individual latencies in a batch style or “90 day cycle” method of vulnerability management cause that method to be less efficient, less secure, and to cause more disruption to an organization than continuous vulnerability management.

So why doesn’t everyone do Continuous Vulnerability Management instead of Batch or Cycle Style Method?

There are some requirements you must meet in order to successfully implement a continuous vulnerability management program. These requirements are not usually cheap or easy.

  • Requires Constant or “Continuous” monitoring

Sound easy? It isn’t for large organization that may have millions of possible IP addresses. You must spend a lot of time and effort in order to get systems setup that can continuously monitor your entire vulnerability footprint. The larger your organization, the harder this requirement will be to implement.

  • Requires near real-time status updates

The ability to scan for vulnerabilities continuously and the ability to report on what has changed from one day to the next is getting much more feasible to accomplish. Some modern vulnerability management systems will keep track of what has changed for you. This “continuous” updating is needed to truly understand when vulnerabilities are found, and when they go away. Without this seemingly simple capability, you must stay in batch mode.

You also need the ability to throw out the vulnerability findings you don’t care about, and figure out which ones you do in a very streamlined or automated fashion. Otherwise you get overloaded with useless data, and the important findings get less focus.

A side-bar to this requirement is that you need reporting and analysis on your data.

Constant remediation can hide pervasive issues unless adequate analysis and trending is performed on discovered vulnerabilities.

Continuous is also all about continuous improvement. Without the ability to analyze and trend data, you are not leveraging continuous compliance/vulnerability management  methods. You probably are not getting the visibility or management support you need without this reporting.

  • Self-Service and Automation Required for Mid size or Large organizations.

This gets even harder. You must automate. Taking raw vulnerability findings from scanning systems and software and turning those into actionable items is very difficult.

If you have hundreds of thousands of systems, and hundreds of possible owner teams, how do you easily or quickly know who owns each vulnerability? If you have a CMDB that has all this mapped out or only have a few thousand systems then great, that is a good start.  Manual analysis of findings from spreadsheets and then sending those spreadsheets out to the owners is not continuous, it is a batch style scenario.  The only way to move from that batch style scenario is to apply logic and rules to your vulnerability data so that the owner for the item and the decision on whether action is needed is automated. Some type of ticketing system that flows the work down to the owners is typically needed.

Organizations with immature vulnerability management and security practices will probably need to remain in a batch style method of vulnerability management until they can meet the above requirements.

Downsides to Continuous vs Batch?

  • Some types of changes or implementations can be done more efficiently in batches.
  • Some organizations may perform better using a batch style method of vulnerability management.

Some of the other topics that seemed to back up the continuous approach..

PCI-DSS: Vulnerability Duration & Scan Frequency – Not Quarterly Scans.

Why Vulnerability Duration is the key metric in vulnerability management for high risk findings.

Some compliance standards (PCI-DSS) require quarterly scans of your external and internal networks that are “in scope” for your specific compliance related systems or networks.

Why Quarterly Scans?

Requiring quarterly vulnerability scans and remediation is an easy way to set a minimum standard for scanning and remediation of vulnerabilities. Quarterly scans should be considered a “low standard”, where continuous compliance and continuous vulnerability scanning are the widely accepted goal that companies should be working toward.

Why Not Quarterly Scans?

There are some fairly basic timing issues you run into requiring quarterly vulnerability scans and remediation that put an unreasonable burden on large companies while not truly improving security over other methods.


So the requirement is that you Scan AND Remediate vulnerabilities within a 90 day window. So what if it takes 2 weeks to run a scan on your several million IP addresses, and maybe another week or so to run your application scanning on 30 or 40 web applications and put together your list of findings.  You are now easily 30 days into your 90 day window.

Now you get the scan results, process the thousands of findings (because vulnerability scanners tell you everything from what ports are open to missing patches) to determine what truly needs to be worked on, and determine who needs to fix which findings. You are now easily 40 days into your 90 day window.

Next you communicate your findings to the folks that can actually resolve the findings and try to determine who is going to work with you and what they can plan to do, (because they always act like the findings are a surprise even though they have been getting them every 90 days for the past 3 years). This easily puts you 50 days into your 90 day window.

So no problem. We now have 40 days left out of 90 to

1) change requirements for release schedules,

2) make code changes and go through Q/A processes,

4) change priorities for entire infrastructure teams,

5) ask various application teams to go through testing and Q/A for webserver configuration changes.

6) Go through all the normal change control documentation and bureaucracy associated with any decent sized IT shop’s change control process.

7) Validate all of the vulnerabilities have been resolved.

Wait! So that 40 days (not business days, only about 28 business days, or around 5-6 weeks at best) doesn’t seem very long anymore. The more mature of an IT company you are, with more mature testing and Q/A and prioritization requirements you have around your business, the harder it is for you to stop on a dime and change priorities.

What is the alternative???

I feel the true intent of requiring a 90 day window for vulnerability scans and remediation is to ensure that you are regularly looking for and resolving security vulnerabilities.  I propose that measuring “Vulnerability Duration” is more important that requiring quarterly scans. I explain why below.

Vulnerability Duration?

Vulnerability Duration can be defined as the duration of time between when a vulnerability is found, and the time when it is resolved.

What is the difference between Vulnerability Duration and Quarterly scans?

The important difference is that requiring quarterly scans assumes that you have short window of time needed to scan and report vulnerabilities. However, for large companies this simply isn’t possible yet. So requiring quarterly scans and remediation requires a large company to typically only have a month or less to remediate vulnerabilities, because much time is needed to get “workable” findings, and run validation scans on the vulnerabilities within that 90 day window also.

This means that requiring quarterly scans only gives large companies about 30 days or so to react to vulnerabilities. Is this the true intent of the quarterly scan requirement???

Also, the quarterly scan requirement also allows vulnerabilities to exist in environments for over 90 days. If a vulnerability is created shortly after a scan, it can exist undetected for a full 90 days (or more) until the next scan in the next quarter is run.

What is the Point I really want to make??

Vulnerability Duration focuses on the true amount of time that a vulnerability exists in an environment, and doesn’t focus on an arbitrary 90 day window for performing specific actions of vulnerability management. Vulnerability duration focuses on the important stuff. It focuses on how long a vulnerability exists and keeps that duration small.

Measuring “Vulnerability Duration” requires the “Continuous Compliance” mindset. If I can scan  for vulnerabilities every 2 weeks or as often as possible, I have the ability to distribute scan findings much more often than every 90 days. This should create a much smaller window of time that vulnerabilities can exist in my environment because vulnerabilities are….

1) Being found much more quickly.. And

2) Vulnerabilities are resolved much closer to the time that they are found.

What does it take to pull this off?

In order for the focus on Vulnerability Duration to be effective you must be scanning for vulnerabilities as often as possible. This means as soon as one scan ends, the next begins. This constant scanning and reporting of vulnerabilities creates the time saving loop that should create a much shorter window of time that vulnerabilities exist.

Analogy – Leaky Boat

I have a leaky boat. The general estimate is that the boat can keep afloat for a week with a leak. So I only check for leaks once a week. Some weeks, no leaks at all. Some weeks, there is a lot of water in the engine room. On a really bad week, there are several leaks and the boat sinks. If I check for leaks and fix them every day there is much shorter amount of time available for any leaks to flood the boat and cause damage. Although not perfect, I think this analogy makes sense.

Why post this at all?

My whole point is that a PCI assessor,  PCI QSA, acquiring banks, and the PCI Council should consider that quarterly scans are a bare minimum that has been set. Requiring the outdated mindset of having to create quarterly reports can hamper the ability for companies to move forward with a “Continuous Compliance” mindset where they are scanning and remediating all the time and measuring vulnerability duration instead of focusing on this quarterly scan and report requirement.

Alternative to the PCI Quarterly Scan requirement?

Allow an alternative reporting method instead of quarterly scans only. Something like having a PCI ASV attest that scans are taking place more often than every 90 days and that the vulnerability duration of any PCI impacting findings do not reside more than 90 days. Anything open more than 90 days would require some type of documentation.

Your Internet Presence and Vulnerability Mgmt

If you get put in charge of vulnerability management for a large organization with many internet facing websites, you may run into some roadblocks on

1) Determining who owns what websites,

2) What servers host which websites.

3) What virtual IP’s load balance to which internal webserver hosts.

4) Which different outsourced entities have ownership over different websites and IP ranges.

5) Getting a listing of your total internet facing IP ranges.

6) Determining which websites and IP ranges are hosted by your company, and which are 3rd party.

7) Determining which websites process any PCI or PII data.

Compliance, Security and Religion

A strange analogy crossed my mind the other Sunday. The whole IT Compliance vs
struggle is a lot like a common struggle in most religion.

A common logic used in religion is to

1) Follow the laws of the religion and

2) Follow the principals of the religion as you understand them.

Following the laws and principals would be doing something “right”, and not following them would be doing something “wrong”.

Laws or Commandments

Compliance regulations are like the “law” or commandments handed down as
non-negotiables in religions. You will or will not do these things. If you break
these rules you will be punished somehow. There is not much grey area when
it comes to following laws and regulations.


However, general IT security is more like the adherence to the principals
behind the teachings of the religion. How diligently or zealously you follow
and take action on the principals of IT security can cause folks to either admire,
despise, or think you are a radical of some sort. Also, the possibility for a “grey area”
delima is much more common when it comes to principals.

The Dilemma
So what about when there is no clear-cut answer on if something is following the
principals of security or your religion? This is where you must fall back on
risk based decision making. In most religions, the Risk of someone perceiving you
are doing something wrong is enough to give you guidance on how to act.

Security decisions can often be based on the same risk decision. If your customers or others
could have the perception of you doing something wrong or irresponsible, then your
course of action should be to stay far clear of doing anything to cause that perception.

A Code of Ethics can also help reduce confusion around security decision making. That’s just one reason why professional organizations help provide guidance for security professionals.

Vulnerability Scanning For Network Appliances

Are you shipping network appliances that haven’t been scanned for vulnerabilities?

I’m responsible for getting security vulnerabilities corrected or “remediated” at work. Keep in mind this is no small job since our network is probably one of the largest in the world.

I continue to be surprised by these network equipment manufacturers that are completely clueless about vulnerability management and the vulnerability footprint of their devices.   These devices are often shipped full of security holes from the factory.

Below I will list some very simple steps that every network appliance manufacturer can do to reduce their customer’s security headaches.

  1. Always run a vulnerability scanner against your device or appliance before you “finalize” the revision for testing. Fix the security holes then start testing.
  2. Ship your “default config” without services needed that expose or open up security holes. This is also known as “secure by default.”  This means instead of having everything the customer could possibly need already up and running, give them an easy way to turn on what they need.
  3. If your default shipping config exposes something that vulnerability scanners pick up on as a vulnerability, or even an informational exposure, Document This information. This will save your security folks work and make your company actually seem professional.
  4. Realize that the security of your appliance is your responsibility as the appliance manufacturer. Be proactive.

It is only a matter of time before some major breach occurs via some “appliance” that was shipped full of security holes from the manufacturer. How will your company reputation be damaged from the fallout?

Database Patching

Don’t forget about Databases!

Since SQL server was affected by the recent patch Tuesday, I realized that databases are a large space in the Enterprise that may have not been getting the focus they need.

In many large companies a separate team (or teams) own and manage the database engine, whether that is SQL server, DB2, Oracle, etc..  How much time has been spent on making sure that there is a solid patching plan for operating systems and networking equipment compared to major “infrastructure applications” like database engines?

Sure, you have to secure the system to have any hope of securing data and applications, but database engines are almost their own little world that ride on top of the operating system.    Here’s why.. Databases…

1) have their own ports they open up,

2) often have their own user management systems that may or may not tie in to your authentication directory,

3) have their own security vulnerabilities that are widely publicized,

4) Are a #1 target for hackers.

Do I really need to give any more reasons that a solid lifecycle management and patching program for database engines is as critical as your patching and lifecycle management for your operating systems and networking equipment?

Surprisingly, your database engineers may be happy to get extra push for upgrades and patches. They often want to apply them but can’t get the cooperation of their customers for testing etc..

Scans Versus Penetration Tests

What is the difference between scanning and penetration testing?

Those of us responsible for managing Vulnerability scanning and penetration testing often seem to get the same question over and over… What is the difference between a vulnerability scan and a penetration test?

You would think that this is not a difficult topic to grasp, but some folks really do struggle to remember the difference. I’ll lay it out here in the most simple way I know how..

  • Scan = Look for holes and issues on a network or website. Usually with some type of scanning tool.
  • Penetration Test = Exploit and Hack holes that you have found on a network. And see how far you can get. A penetration test often starts with a scan, but is not limited to just the scanning.

Some good scanning tools are..

McAfee Vulnerability Manager (used to be called Foundstone)



Many companies offer penetration testing services.  I’ve only had experience with a few, so my only advice is to make sure your contracts are well written and that you are careful when working with a small company.