McAfee Secure Short-URL Service Easy to Foil

McAfee have launched a Beta URL shortening service with added security features. As Brett Hardin pointed out they are a little late to the game. However, there are so many abuses of URL shortening services that I commend them for trying.

Basically, what their service does is allow you to create short easy URLs (like any other service). However, unlike other services, when you click on the link, it opens a frames page with the content in the bottom frame and the McAfee information in the top frame. This information includes details about the domain you are connecting to, the type of company it's registered to and a big green tick or red cross to tell you whether the site is safe or not. This is decided by their 'Global Threat Intelligence', which will block known bad URLs and phishing sites. That's good, if it works.

I said above that I commend them for trying to provide this service. There are some obvious failings in their solution though, that render their protections useless other than to make it easier for people to phish users as the page has the McAfee stamp of approval. Below is their site working properly to block a known bad phishing URL.


As you can see, this site was blocked and marked as a phishing URL, which it was. Excellent, it's working! Hold on a minute though. Have a look at the screenshot below where I can access the same URL through their service by embedding it in an iframe. I now get the big green tick and I'm told that it is safe. You can see from the source that the iframe is showing the exact same URL as was blocked before. Incidentally, the page says that the site is a Business Internet Services company, which is extremely misleading as I can assure you that this wasn't put on a domain run by a Business Internet Services company.


Also, what about if I code my page to not accept being in a frames page? Then the service falls down again. The screenshot below is of Twitter accessed through this service. The problem is that I can hide all sorts of other links in the page to fool McAfee and the user won't see them. I know McAfee will block these URLs in time, but they will only be blocking the host page and they will have to block all of them. Also, if you click on a link within the page that directs you to another domain, then that is not checked, so I could just redirect you to a phishing URL and you'll still get the big green tick.


It's a nice idea, but it just doesn't work. Interestingly, other services also have some security in them. TinyURL, for example, wouldn't allow me to create a short URL for this phishing site in the first place as it was recognised as such. McAfee happily let me produce the short URL, they just blocked it later - not such a good strategy in my opinion. I know that a new phishing URL would fool TinyURL as well, but I particularly chose a URL that had been around for the best part of a month to give them a chance and I think TinyURL has done better. Incidentally, TinyURL also allowed me to produce a short URL for my test page. One good thing about TinyURL is the preview facility, but that doesn't protect me against a site that looks like the real thing.

Moral: follow any links at your own risk and don't think that a green tick makes it safe!

Telephone Systems a Hackable Backdoor?

I have been talking to a company that provides telephone exchanges and services to companies this week on behalf of a client and it has highlighted a worrying backdoor. It turns out that many of these companies have a way to remotely connect to their exchange for support purposes - they can remotely control, configure and troubleshoot your system to get you back up and running. Exchanges often have additional modems in them to allow for remote connections. This is all very well and good from a managed service point of view, but what about the rest of your network? Can this be exploited to gain entry to your network? Quite possibly in some cases - it certainly needs to be included in your security audit and perimeter testing.

Talking about a specific company now, they supply the software to monitor and bill phone calls through the exchange. They remotely install, monitor and manage this software. How do they do that? Well, it turns out that they install LogMeIn on your machine. Now this will make outbound connections through the firewall to make the internal machine accessible from the outside world. Hang on; you're making my networked machine that controls my exchange and billing accessible by anyone? By default LogMeIn will use simple username/password type authentication.

The user who accesses the computer has to set up their account with LogMeIn and will use the same username and password combination on all machines as far as I can see. Does the company have a universal account that they use to remotely access the machines or does each user have their own? If the company uses one default username/password, then what happens if someone gets hold of that information or someone leaves? Does the password get changed? If everyone has their own account, then are they removed when they leave the company? As this is all done through the Web, they could still gain access if they aren't specifically removed from the user group.

How much do you trust all the employees of that external company? How much do you trust the disgruntled ex-employee from them who has access? It might not be that they are trying to attack you, but they may be careless about the credentials or not revoke them properly. Also, consider the case where all the internal employees of an organisation are required to have 2-factor authentication and remote access is locked down. What's the point? There is a simple username/password entry point into the network that bypasses all the secure remote access services you may have in place. How secure are the passwords that the external company use? Would they match up to your complexity requirements? If they are simple, easily guessed or shared, then they open full administrative control over a machine on your 'secure' internal network. Who patches the machine and who updates LogMeIn?

How about installing a keylogger in such a firm to pick up on their username/password combinations so that you can gain full access to every customer's network. Once on the internal machine, malware can easily be installed and attacks launched on other internal machines unhindered. How many organisations have followed best practice and installed a UTM firewall in the core of their network to segregate their servers, etc., from other internal machines? Would a machine running this software be on a normal user subnet or on the management subnet anyway? Do many SMEs have more than one subnet anyway?

Needless to say, my advice was to avoid installing LogMeIn on the machine and temporarily allow a more controlled access to the machine with a temporary account, all of which can be disabled immediately after remote installation is completed. This opens up the problem of how to obtain support, but access can be temporarily granted and then removed when support is required with relatively little effort.

Clearly any such system needs to be well documented and be part of the security audit. I would advise that companies also ask for security audit and policy information from any external company who has any kind of access to the network - this should be standard procedure.

Human Factors in Information Security - Errors & Violations

Human failures are often described as Slips, Lapses, Mistakes and Violations. These are grouped into two categories: Errors and Violations. The difference here is the intent - violations result from conscious decisions to disregard policies and procedures, whereas errors have no malicious intent. Also, violations often involve more than one form of misconduct, whereas errors are often isolated.

Don Turnblade has stated that in his experience "well trained staff had a 3.75% unintentional non-compliance rate; they did not realize that installed software compromised data security. About 0.4% of end users were intentionally non-compliant, generally willful persons with strong technical skill or organizational authority who were unaccustomed to complying with computing restrictions."

So what are the different types of error? Dealing with each in turn, we have Slips, Lapses and Mistakes.

• Slips - actions not carried out as intended, e.g. pressing the wrong key by accident. Slips usually occur at the task execution stage.
• Lapses - missed actions or omissions, e.g. forgetting to log out, or a step in a configuration process.
• Mistakes - occur due to an incorrect intention, whilst believing it to be correct, i.e. they are deliberate actions with no malicious intent, e.g. misconfiguration of a firewall. Mistakes usually occur at the planning stage.

So who causes the error or violation and how do we combat them? Slips and Lapses are usually the fault of the user, but can be mitigated by making it more difficult for the user to make the error, e.g. by having confirmation dialogs for slips and better training for lapses. Mistakes tend to be the fault of designers and are slightly more difficult to combat as designer education is required or outside technical expertise needs to be brought in. However, this doesn't always solve the problem if they don't have the skills and knowledge required. Finally, violations can often be laid at the door of the managers. It is often the case that a culture of violations is accepted by senior management, who fail to impose proper sanctions or take the threat seriously.

All of these have to be dealt with to have a secure system and most of it boils down to having proper user education and training in place.

Should an Administrator Trust their Users?

The answer is yes and no (note, in this blog, I'm not talking about cryptographic or identity trust, but systems trust). There are two aspects to this. Firstly, do you think your users will deliberately act against your organisation or try to harm the system? This is not usually the case for corporate employees - you also have severe sanctions available if they do. The second aspect is, do you trust your users NOT to make mistakes? Everyone makes mistakes; we're only human. You don't want accidental updates or changes, so in this sense maybe you shouldn't trust your users.

Actually there are three overall approaches to system trust on networks. We can trust all of the people all of the time (bad idea, but much more common than you'd think), trust no one at any time (maybe too excessive and hinder functionality), or we can trust some of the people some of the time. The last one is usually the best strategy to adopt for your network.

Finally, we have to decide on the overall approach to security. Are we permissive or restrictive? In a permissive environment you can do everything, apart from those things on a blacklist. In a restrictive environment, you can do nothing, apart from those things on a whitelist. From a security standpoint restrictive is better, but from a usability standpoint permissive is better. If you can manage the whitelist successfully, this is the better solution and only trust some of the users some of the time.

Lack of true Identity Verification forces need for EV SSL Certificates

What are EV SSL Certificates? Simply they are Extended Validation SSL Certificates. What does this mean? Well, simply put the Certification Authority goes to more lengths to validate the identity of the person asking for (paying for) the certificate. The EV SSL Certificate then will make the browser address bar go green to certify that this really is the site you think it is and not a phishing or pharming site. It gives the user a very visual check of the validity of the website that they are using.

Isn't this what Digital Certificates were supposed to do in the first place? Yes, but the Certification Authorities were more interested in taking people's money than verifying that they actually were the people in question. This led to almost anybody being able to sign up for a certificate claiming to be almost anybody. This, obviously, isn't a workable situation, so EV SSL Certificates were introduced to do the intended job, only at a higher price than the standard SSL Certificate (in part due to the actual identity validation performed no doubt). That being said, they are not expensive in the grand scheme of things and should be used far more widely than they currently are - for example NatWest still doesn't use an EV SSL Certificate at the time of writing this, instead they have ended up implementing Trusteer's Rapport at a much higher cost.

To give you some idea of cost of a digital certificate, Comodo's price is £214 per year (US$359/€359) for a single fully qualified domain name (i.e. per website); this includes their 'Corner of Trust' logo. Compare this with somewhere near $1 per customer for Trusteer's Rapport or even hosting fees and business profits! Admittedly, their cheapest SSL Certificate is only £41.95 per annum, but is £214 too much to ask when you are giving customers peace of mind, assurances over authentication and tackling phishing & pharming?

Why aren't normal certificates secure? Well, the problem is that most Certification Authorities don't do very much checking. Usually they check your domain name by sending you an email to an address that has the same domain name extension. All this says is that someone who has access to an email address on that domain wants to set up a secure web server. They don't actually check who you are. They are more interested in whether you will pay than if they should issue the certificate. This was demonstrated at IPICS today, when it was shown that VeriSign had given out a Digital Certificate to someone using the name William Gates! They have also fallen for scams, where they were duped into issuing a code signing certificate for the Microsoft Corporation by someone proving the point that they are not careful enough.

I decided to see if this was the case with other organisations, and it is. I have set up an SSL certificate just by being able to view an email sent to an address on that domain. I also wanted to know if I could be Steve Ballmer - the new Bill Gates. So, I set up an email account: Steve.Ballmer@live.co.uk using details about him, such as his year of birth: 1956. I then decided to try Thawte out, as they provide free email certificates for personal use. Sure enough, after entering the data below, I was sent an email to my address with codes to verify myself. I now have a digital certificate to sign emails from Steve.Ballmer@live.co.uk.

Surname: Ballmer
Forenames: Steve
Date Of Birth: 1956/03/24
Nationality: the United States
Email: steve.ballmer@live.co.uk
Where were you born? Detroit
Where did you go to school? Detroit Country Day School
First company you worked for? Procter & Gamble
What is your spouse's Name? Connie Snyder
How many children do you have? 3

Now, Thawte has a little trick up its sleeve here, which aides security. Before they will assign the name Steve Ballmer to the certificate, I must pass their Web of Trust, i.e. I must convince some other users that I am indeed Steve Ballmer first by meeting them face-to-face. However, if I could supply them with details such as passport number and social security number, then I'd be set. So, I can still sign my email, but if users look closely at the signature and check the certificate, they will see that I haven't been verified. However, if they don't actually look at this carefully, and with knowledge of what it means, then they will be fooled into thinking I really am Steve Ballmer. Why should the ordinary user know about this? Comodo and VeriSign, on the other hand, provide no such backup. So, I can now sign my email as Steve Ballmer. Here's my Public Key for Steve Ballmer from Comodo showing that I really am Steve Ballmer!

This isn't really good enough in this day and age of phishing scams.

Post Script Edit
Two things have happened since writing this blog post. Firstly, I have become aware of an attack on SSL Certificates by using a null value inserted in the domain name to trick the CA into issuing a certificate on an invalid domain. For example, www.natwest.com[null value].phishers.org will result in an SSL certificate being issued for www.natwest.com to the phishers.org site, which will appear valid in many browsers (but not all). Link to blog post. This won't (shouldn't) affect EV SSL Certificates though, only the Domain Validated ones.

Secondly, Comodo, to their credit, do admit that this is a problem and are takling it. They have sent me a link via email to a video clip, which in turn links to more information. That can be found here. The bottom line really is that these EV certificates are more secure, don't cost that much and should be the norm. As an industry we should be educating users into recognising and looking for these security features.

Obstacle Poker for Security Assessments

I was talking to Vic Page, a colleague of mine, today about various things and he told me about one of his PhD deliverables on 'Three Card RAG' or 'Obstacle Poker' - very interesting concept that he has come up with. During our discussion, we came up with an embryonic idea for using his concept to aide security assessments of organisations. Before I can describe it I need to extract a few concepts from his 10-page paper in the BT Technology Journal entitled "Security risk mitigation for information systems".

In the paper he describes the Security Obstacle Mitigation Model (SOMM) for developing trustworthy information systems. He also defines some terminology - a subset of which I have reproduced here (his paper is an interesting read):

• mitigation - a mitigation is a procedure that will counter the effect of an obstacle


• obstacle - an obstacle is something that, should it occur, will obstruct a trust assumption and affect the CIAA security requirements - obstacles are caused by malicious or inadvertent use of the operational information system


• RAG code - RAG codes form an intuitive 'traffic light' approach to ranking the ability for load-bearing and the vulnerability of a trust assumption (RAG is an acronym for Red, Amber and Green). R signifies stop and mitigate, A signifies proceed with caution and G signifies continue with trust

So how is this relevant to security assessments particularly rather than information systems in general? Well, it is the way he is applying it that becomes interesting for the security assessment arena. He has moved this concept into the field of agile development and taken the Scrums process of planning poker and made it more accessible for other fields.

Now a quick background to the security assessment field is in order. The majority of security assessment strategies are technology focused and concentrate on system evaluation and tactical issues. This can lead to point solutions and, therefore, gaps between countermeasures. Obviously we need the vulnerability assessments and information system audits, but these should follow an Information Security Risk Evaluation. Schemes like Octave, although big, do follow an organisational evaluation, focused on security practices and strategic issues. The top down approach is driven by business issues and objectives leading to protection of what needs it and awareness of risk. Most other bottom up security practices start with individual components and computing infrastructure, seeking the technological 'silver bullet', which leads to protecting what can be protected rather than what needs to be protected. Of course this is an ongoing cyclical process.

So, what is obstacle poker and how do we incorporate it into an information security risk evaluation? Well, the principle is that representatives of all roles must be included in an information security risk evaluation for it to meet the needs of the organisation. Too often security assessments are left to the ICT departments and technologists, who don't necessarily know the business processes at play. Unfortunately, the people working in the organisation who aren't part of the ICT team usually have little or no knowledge of the technical landscape or what's possible/feasible. It needs everyone at the table and they need to speak a common language. Interpreters, i.e. consultants, can be brought in to help, but there still needs to be a simple way to converse.

The idea of 'Three Card RAG' is that an issue is discussed and then all the members of the team will rate it with the RAG scale given above. This is done by issuing each member of the team three cards - one Red, one Amber and one Green. Each member picks a card and then everyone reveals their cards at once. If everyone agrees, then that is considered the state of play and actions are taken accordingly. If they do not agree then further discussion can be entered into and another round completed. The idea being to come to a consensus between the technical experts and the users of the system quickly and efficiently. Those that are more obvious will be dealt with very quickly, those requiring more discussion will be given a fair hearing.

This principle can be used in information security risk evaluation by identifying the threat ratings and consequences of risks. We all know that a Threat + a Vulnerability = Risk to an Asset, but how can we categorise these when ICT and management departments can be approaching this from very different standpoints? Is the system that seems critical to the ICT department actually critical to the business or not?

Threat ratings have the following defined ranges: Negligible, very low, low, medium, high, very high and extreme. They are quite well defined in terms of how often they are likely to occur, from unlikely, through likely to occur every 6 months or less for medium, to likely to occur multiple times each day for extreme. These threat ratings must be ICT lead, but not exclusively controlled. If everyone holds a green card then it can be classified as very low or negligible. Amber would denote Medium and red would denote very high or extreme threat rating. Mixtures of cards can result in the low or high ratings being used if there is still no total agreement after a few rounds. The consequences are where the ICT department may step back a little. These are defined by the Australian Government's Defence Signals Directorate as:

• insignificant - can be dealt with by normal operations
• minor - could threaten the system’s efficiency or effectiveness but can be dealt with internally
• moderate - does not threaten the system, but could cause major review and modification of operating procedures
• major - threatens the continuation of basic functions of the system and requires senior-level management intervention
• catastrophic - threatens the continuation of the system and causes major problems for the organisation and customers

This is where Three Card RAG really comes into its own. Getting agreement on this scale can be very difficult in organisations. However, with a simple traffic light scheme, everyone understands the system and agreement can be reached much more easily between all the stakeholders. Simply put, if it's red it's a priority, amber is secondary and green can be safely ignored until the next iteration (N.B. not ignored completely or never discussed again, just not dealt with in the current round of the cycle).