Scangate Re-visited: Vulnerability Scanners Uncovered

I have covered VA tools before but I feel that one year later, the same misconceptions prevail. The notion that VA tools really can be used to give a decent picture of vulnerability is still heavily embedded, and that notion in itself presents a serious vulnerability for businesses.

A more concise approach at a run down on the functionality of VA warez may be worth a try. At least lets give it one last shot. On second thoughts, no, don’t shoot anything.

Actually forget “positive” or “negative” views on VAs before reading this. I am just going to present the facts based on what I know myself and of course I’m open to logical, objective discussion. I may have missed something.

Why the focus on VA? Well, the tools are still so commonplace and heavily used and I don’t believe that’s in our best interests.

What I discovered many years ago (it was actually 2002 at first) was that discussions around these tools can evoke some quite emotional responses. “Emotional” you quiz? Yes. I mean when you think about it, whole empires have been built using these tools. The tools are so widespread in security and used as the basis of corporate VM programs. VM market revenues runs at around 1 billion USD annually. Songs and poems have been written about VAs – OK I can’t back that up, but careers have been built and whole enterprise level security software suites built using a nasty open source VA engine.

I presented on the subject of automation in VA all those years ago, and put forward a notion that running VA tools doesn’t carry much more value as compared to something like this: nmap -v -sS -sV <targets> . Any Security Analyst worth their weight in spam would see open ports and service banners, and quickly deduce vulnerability from this limited perspective. “Limited”, maybe, but is a typical VA tool in a better position to interrogate a target autotragically?

One pre-qualifier I need to throw out is that the type of scanners I will discuss here are Nessus-like scanners, the modus operandi of which is to use unauthenticated means to scan a target. Nessus itself isn’t the main focus but it’s the tool that’s most well known and widely used. The others do not present any major advantages over Nessus. In fact Nessus is really as good as it gets. There’s a highly limited potential with these tools and Nessus reaches that limit.

Over the course of my infosec career I have had the privilege to be in a position where I have been coerced into using VAs extensively, and spent many long hours investigating false positives. In many cases I set up a dummy Linux target and used a packet sniffer to deduce what the tool was doing. As a summary, the findings were approximately:

  • Out of the 1000s of tests, or “patterns”, configured in the tools, only a few have the potential to result in accurate/useful findings. Some examples of these are SNMP community string tests, and tests for plain text services (e.g. telnet, FTP).
  • The vast majority of the other tests merely grab a service “banner”. For example, the tool port scans, finds an open port 80 TCP, then runs a test to grab a service banner (e.g. Apache 2.2.22, mickey mouse plug-in, bla bla). I was sort of expecting the tool to do some more probing having found a specific service and version, but in most cases it does not.
  • The tool, having found what it thinks is a certain application layer service and version, then correlates its finding with its database of public disclosed vulnerabilities for the detected service.

Even for some of the plan text services, some of the tests which have the potential to reveal useful findings have been botched by the developers. For example, tests for anonymous FTP only work with a very specific flavour of FTP. Other FTP daemons return different messages for successful anonymous logins and the tool does not accommodate this.

Also what happens if a service is moved from its default port? I had some spectacular failures with running Nessus against a FTP service on port 1980 TCP (usually it is listening on port 21). Different timing options were tested. Nessus uses a nmap engine for port scanning, but nmap by itself is usually able to find non-default port services using default settings.

So in summary, what the VA tools do is mostly just report that you are running ridiculous unencrypted blast-from-the-past services or old, down-level services – maybe. Really I would hope security teams wouldn’t need to spend 25K USD on an enterprise solution to tell them this.

False positives is one thing, but false negatives is quite another. Popular magazines always report something like 50% success rate in finding vulnerabilities in staged tests. Why is it always 50%? Remember also that the product under testing is usually one from a vendor who pays for a full spread ad in that magazine.

Putting numbers to false negatives makes little sense with huge, complex software packages of millions of lines of source code. However, it occurred to me not so long ago whilst doing some white box testing on a client’s critical infrastructure: how many of the vulnerabilities under testing could possibly be discovered by use of a VA tool? In the case of Oracle Database the answer was less than 5%. And when we’re talking Oracle, we’re usually talking critical, as in crown jewels critical.

If nothing else, the main aspect I would hope the reader would take out of this discussion is about expectation. The expectation that is set by marketing people with VA tools is that the tools really can be used to accurately detect a wide range of vulnerability, and you can bet your business on the tools by using them to test critical infrastructure. Ladies and gentlemen: please don’t be deceived by this!

Can you safely replace manual testing with use of these tools? Yes, but only if the target has zero value to the business.

 

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Security in Virtual Machine Environments. And the planet.

This post is based on a recent article on the CIO.com site.

I have to say, when I read the title of the article, the cynic in me once again prevailed. And indeed there will be some cynicism and sarcasm in this article, so if that offends the reader, i would like to suggest other sources of information: those which do not accurately reflect the state of the information security industry. Unfortunately the truth is often accompanied by at least cynicism. Indeed, if I meet an IT professional who isn’t cynical and sarcastic, I do find it hard to trust them.

Near the end of the article there will be a quiz with a scammed prize offering, just to take the edge of the punishment of the endless “negativity” and abject non-MBA’edness.

“While organizations have been hot to virtualize their machine operations, that zeal hasn’t been transferred to their adoption of good security practices”. Well you see they’re two different things. Using VMs reduces power and physical space requirements. Note the word “physical” here and being physical, the benefits are easier to understand.

Physical implies something which takes physical form – a matter energy field. Decision makers are familiar with such energy fields. There are other examples in their lives such as tables, chairs, other people, walls, cars. Then there is information in electronic form – that’s a similar thing (also an energy field) but the hunter/gatherer in some of us doesn’t see it that way, and still as of 2013, the concept eludes many IT decision makers who have fought their way up through the ranks as a result of excellent performance in their IT careers (no – it’s not just because they have a MBA, or know the right people).

There is a concept at board level of insuring a building (another matter energy field) against damages from natural causes. But even when 80% of information assets are in electronic form, there is still a disconnect from the information. Come on chaps, we’ve been doing this for 20 years now!

Josh Corman recently tweeted “We depend on software just as much as steel and concrete, its just that software is infinitely more attack-able!”. Mr Corman felt the need to make this statement. Ok, like most other wise men in security, it was intended to boost his Klout score, but one does not achieve that by tweeting stuff that everybody already knows. I would trust someone like Mr Corman to know where the gaps are in the mental portfolios of IT decision makers.

Ok, so moving on…”Nearly half (42 percent) of the 346 administrators participating in the security vendor BeyondTrust‘s survey said they don’t use any security tools regularly as part of operating their virtual systems…”

What tools? You mean anti-virus and firewalls, or the latest heuristic HIDS box of shite? Call me business-friendly but I don’t want to see endless tools on end points, regardless of their function. So if they’re not using tools, is it not at this point good journalism to comment on what tools exactly? Personally I want to see a local firewall and the obligatory and increasingly less beneficial anti-virus (and i do not care as to where, who, whenceforth, or which one…preferably the one where the word “heuristic” is not used in the marketing drivel on the box). Now if you’re talking system hardening and utilizing built-in logging capability – great, that’s a different story, and worthy of a cuddly toy as a prize.

“Insecure practices when creating new virtual images is a systemic problem” – it is, but how many security problems can you really eradicate at build-time and be sure that the change won’t break an application or introduce some other problem. When practical IT-oriented security folk actually try to do this with skilled and experienced ops and devs, they realise that less than 50% of their policies can be implemented safely in a corporate build image. Other security changes need to be assessed on a per-application basis.

Forget VMs and clouds for a moment – 90%+ of firms are not rolling out effectively hardened build images for any platform. The information security world is still some way off with practices in the other VM field (Vulnerability Management).

“If an administrator clones a machine or rolls back a snapshot,”… “the security risks that those machines represent are bubbled up to the administrator, and they can make decisions as to whether they should be powered on, off or left in state.”

Ok, so “the security risks that those machines represent are bubbled up to the administrator”!!?? [Double-take] Really? Ok, this whole security thing really can be automated then? In that case, every platform should be installed as a VM managed under VMware vCenter with the BeyondTrust plugin. A tab that can show us our risks? There has to be a distinction between vulnerability and risk here, because they are two quite different things. No but seriously, I would want to know how those vulnerabilities are detected because to date the information security industry still doesn’t have an accurate way to do this for some platforms.

Another quote: “It’s pretty clear that virtualization has ripped up operational practices and that security lags woefully behind the operational practice of managing the virtual infrastructure,”. I would edit that and just the two words “security” and “lags”. What with visualized stuff being a subset of the full spectrum of play things and all.

“Making matters worse is that traditional security tools don’t work very well in virtual environments”. In this case i would leave remaining five words. A Kenwood Food Mixer goes to the person who can guess which ones those are. See? Who said security isn’t fun?

“System operators believe that somehow virtualization provides their environments with security not found in the world of physical machines”. Now we’re going Twilight Zone. We’ve been discussing the inter-cluster sized gap between the physical world and electronic information in this article, and now we have this? Segmentation fault, core dumped.

Anyway – virtualization does increase security in some cases. It depends how the VM has been configured and what type of networking config is used, but if we’re talking virtualised servers that advertise services to port scanners, and / or SMB shares with their hosts, then clearly the virtualised aspect is suddenly very real. VM guests used in a NAT’ing setup is a decent way to hide information on a laptop/mobile device or anything that hooks into an untrusted network (read: “corporate private network”).

The vendor who was being interviewed finished up with “Every product sounds the same,” …”They all make you secure. And none of them deliver.” Probably if i was a vendor I might not say that.

Sorry, I just find discussions of security with “radical new infrastructure” to be something of a waste of bandwidth. We have some very fundamental, ground level problems in information security that are actually not so hard to understand or even solve, at least until it comes to self-reflection and the thought of looking for a new line of work.

All of these “VM” and “cloud” and “BYOD” discussions would suddenly disappear with the introduction of integrity in our little world because with that, the bigger picture of skills, accreditation, and therefore trust would be solved (note the lack of a CISSP/CEH dig there).

I covered the problems and solutions in detail in Security De-engineering, but you know what? The solution (chapter 11) is no big secret. It comes from the gift of intuition with which many humans are endowed. Anyway – someone had to say it, now its in black and white.

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Hardening is Hard If You’re Doing it Right

Yes, ladies and gentlemen, hardening is hard. If its not hard, then there are two possibilities. One is that the maturity of information security in the organization is at such a level that security happens both effectively and transparently – its fully integrated into the fabric of BAU processes and many of said processes are fully automated with accurate results. The second (far more likely given the reality of security in 2013) is that the hardening is not well implemented.

For the purpose of this diatribe, let us first define “hardening” so that we can all be reading from the same hymn sheet. When I’m talking about hardening here, the theme is one of first assessing vulnerability, then addressing the business risk presented by the vulnerability. This can apply to applications, or operating systems, or any aspect of risk assessment on corporate infrastructure.

In assessing vulnerability, if you’re following a check list, hardening is not hard – in fact a parrot can repeat pearls of wisdom from a check list. But the result of merely following a check list will be either wide open critical hosts or over-spending on security – usually the former. For sure, critical production systems will be impacted, and I don’t mean in a positive way.

You see, like most things in security, some thinking is involved. It does suit the agenda of many in this field to pretend that security analysis can be reduced down to parrot-fashion recital of a check list. Unfortunately though, some neural activity is required, at least if gaining the trust of our customers (C-levels, other business units, home users, etc) is important to us.

The actual contents of the check list should be the easy part, although unfortunately as of 2013, we all seem to be using different versions of the check list, and some versions are appallingly lacking. The worst offenders here deliver with a quality that is inversely proportional to the prices they charge – and these are usually external auditors from big 4 consultancies, all of whom have very decent check lists, but who also fail to ensure that Consultants use said check list. There are plenty of cases where the auditor knocks up their own garage’y style shell script for testing. In one case i witnessed not so long ago, the script for testing RedHat Enterprise Linux consisted of 6 tests (!) and one of the tests showed a misunderstanding of the purpose of the /etc/ftpusers file.

But the focus here is not on the methods deployed by auditors, its more general than that. Vulnerability testing in general is not a small subject. I have posted previously on the subject of “manual” network penetration testing. In summary: there will be a need for some businesses to show auditors that their perimeter has been assessed by a “trusted third party”, but in terms of pure value, very few businesses should be paying for the standard two week delivery with a four person team. For businesses to see any real value in a network penetration test, their security has to be at a certain level of maturity. Most businesses are nowhere near that level.

Then there is the subject of automated, unauthenticated “scanning” techniques which I have also written about extensively, both in an earlier post and in Chapter Five of Security De-engineering. In summary, the methodology used in unauthenticated vulnerability scanning results in inaccuracy, large numbers of false positives, wasted resources, and annoyed operations and development teams. This is not a problem with any particular tool, although some of them are especially bad. It is a limitation of the concept of unauthenticated testing, which amounts to little more than pure guesswork in vulnerability assessment.

How about the growing numbers of “vulnerability management” products out there (which do not “manage” vulnerability, they make an attempt at assessing vulnerability)? Well, most of them are either purely an expensive graphical interface to [insert free/open source scanner name], or if the tool was designed to make a serious attempt at accurate vulnerability assessment (more of them do not), then the tests will be lacking or over-done, inaccurate, and / or doing the scanning in an insecure way (e.g. the application is run over a public URL, with the result that all of your configuration data, including admin passwords, are held by an untrusted third party).

In one case, a very expensive VM product literally does nothing other than port scan. It is configured with hundreds of “test” patterns for different types of target (MS Windows, *nix, etc) but if you’re familiar with your OS configurations,you will look at the tool output and be immediately suspicious. I ran the tool against a Linux and Windows test target and “packet sniffed” the scanning engine’s probe attempts. In summary, the tool does nothing. It just produces a long list of configuration items (so effectively a kind of Security Standard for the target) without actually testing for the existence of vulnerability.

So the overall principle: the company [hopefully] has a security standard for each major operating system and database on their network and each item in the standard needs to be tested for all, or some of the information asset hosts in the organization, depending on the overall strategy and network architecture. As of the time of writing, there will need to be some manual / scripted augmentation of automatic vulnerability assessment processes.

So once armed with a list of vulnerabilities, what does one do with it? The vulnerability assessment is the first step. What has to happen after that? Can Security just toss the report over to ops and hope for the best? Yes, they can, but this wouldn’t make them very popular and also there needs to be some input from security regarding the actual risk to the business. Taking the typical function of operations teams (I commented on the functions and relationships between security and operations in an earlier post), if there is no input from security, then every risk mitigation that meets any kind of an impact will be blocked.

There are some security service providers/consultancies who offer a testing AND a subsequent hardening service. They want to offer both detection AND a solution, and this is very innovative and noble of them. However, how many security vulnerabilities can be addressed blindly without impacting critical production processes? Rhetorical question: can applications be broken by applying security fixes? If I remove the setuid bit from a root owned X Window related binary, it probably has no effect on business processes. Right? What if operations teams can no longer authenticate via their usual graphical interface? This is at least a little bit disruptive.

In practice, as it turns out, if you look at a Security Standard for a core technology, lets take Oracle 11g as an example: how many of the numerous elements of a Security Standard can we say can be implemented without fear of breaking applications, limiting access for users or administrators, or generally just making trouble-shooting of critical applications a lot less efficient? The answer is: not many. Dependencies and other problems can come from surprising sources.

Who in the organization knows about dependencies and the complexities of production systems? Usually that would be IT / Network Operations. And how about application – related dependencies? That would be application architects, or just generally we’ll say “dev teams” as they’re so affectionately referred to these days. So the point: even if security does have admin access to IT resources (rare), is the risk mitigation/hardening a job purely for security? Of course the answer is a resounding no, and the same goes for IT Operations.

So, operations and applications architects bring knowledge of the complexities of apps and infrastructure to the table. Security brings knowledge of the network architecture (data flows, firewall configurations, network device configurations), the risk of each vulnerability (how hard is to exploit and what is the impact?), and the importance to the business of information assets/applications. Armed with the aforementioned knowledge, informed and sensible decisions on what to do with the risk (accept, mitigate, work around, or transfer) can be made by the organization, not by security, or operations.

The early days of deciding what to do with the risk will be slow and difficult and there might even be some feisty exchanges, but eventually, addressing the risk becomes a mature, documented process that almost melts into the background hum of the machinery of a business.

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isPasswordOK?

Not sure how resistant is your password to real world hacker password enumeration vectors? There’s an app for that.

The folks over at Literatecode have developed an IPhone app called isPasswordOK to help the average person select a strong password.

When users sign-up for online services they are often asked to give a password. They enter the password, as an example…”Password”, this doesn’t pass the test on the blog sign-up form? However “P4ssw0rd” passes the test (there’s a Javascript “password strength” indicator script that assesses password strength allegedly), but those meters do not take into account real world enumeration/ccracking techniques. Generally the user is told they have a “Good” or “fair” password as long as their password passes the format test (e.g. One upper case, one lower case, one punctuation mark) . Clearly to those in the know, P4ssw0rd is a bad password, but not according to most online registration form strength indicators.

Passwords authentication poses a nightmare for users and security departments. They can’t be too complex because then they get written down somewhere where others can see them (in one case the employee wrote a password on the ceiling board over their desk). Then…obviously they can’t be too simple. But passwords are all we have in many cases, so let’s do our best to choose a good one – and this is not as simple as many folk believe it to be.

This app is a nice innovation, long overdue, and sorely needed, as demonstrated by the myriad of password compromises globally.

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