The Center for Education and Research in Information Assurance and Security (CERIAS)
The Center for Education and Research inInformation Assurance and Security (CERIAS)
[tags]news, cell phones, reports, security vulnerabilities, hacking, computer crime, research priorities, forensics, wiretaps[/tags]
The Greek Cell Phone Incident
A great story involving computers and software, even though the main hack was against cell phones:
IEEE Spectrum: The Athens Affair. From this we can learn all sorts of lessons about how to conduct a forensic investigation, retention of logs, wiretapping of phones, and more.
Now, imagine VoIP and 802.11 networking and vulnerabilities in routers and…. —the possibilities get even more interesting. I suspect that there’s a lot more eavesdropping going on than most of us imagine, and certainly more than we discover.
NRC Report Released
Last week, the National Research Council announced the release of a new report: Towards a Safer and More Secure Cyberspace. The report is notable in a number of ways, and should be read carefully by anyone interested in cyber security. I think the authors did a great job with the material, and they listened to input from many sources.
There are 2 items I specifically wish to note:
More to the point, people who put off the pain and expense of trying to fix things because “Nothing really terrible has happened yet” do not understand history, human nature, or the increasing drag on the economy and privacy from current problems. The trends are fairly clear in this report: things are not getting better.
Evolution of Computer Crime
Speaking of my alleged expertise at augury, I noted something in the news recently that confirmed a prediction I made nearly 8 years ago at a couple of invited talks: that online criminals would begin to compete for “turf.” The evolution of online crime is such that the “neighborhood” where criminals operate overlaps with others. If you want the exclusive racket on phishing, DDOS extortion, and other such criminal behavior, you need to eliminate (or absorb) the competition in your neighborhood. But what does that imply when your “turf” is the world-wide Internet?
The next step is seeing some of this spill over into the physical world. Some of the criminal element online is backed up by more traditional organized crime in “meat space.” They will have no compunction about threatening—or disabling—the competition if they locate them in the real world. And they may well do that because they also have developed sources inside law enforcement agencies and they have financial resources at their disposal. I haven’t seen this reported in the news (yet), but I imagine it happening within the next 2-3 years.
Of course, 8 years ago, most of my audiences didn’t believe that we’d see significant crime on the net—they didn’t see the possibility. They were more worried about casual hacking and virus writing. As I said above, however, one only needs to study human nature and history, and the inevitability of some things becomes clear, even if the mechanisms aren’t yet apparent.
The Irony Department
GAO reported a little over a week ago that DHS had over 800 attacks on their computers in two years. I note that the report is of detected attacks. I had one top person in DC (who will remain nameless) refer to DHS as “A train wreck crossed with a nightmare, run by inexperienced political hacks” when referring to things like TSA, the DHS cyber operations, and other notable problems. For years I (and many others) have been telling people in government that they need to set an example for the rest of the country when it comes to cyber security. It seems they’ve been listening, and we’ve been negligent. From now on, we need to stress that they need to set a good example.
[posted with ecto]
[tags]diversity, complexity, monocultures[/tags]
In my last post, I wrote about the problems brought about by complexity. Clearly, one should not take the mantra of “simplification” too far, and end up with a situation where everything is uniform, simple, and (perhaps) inefficient. In particular, simplification shouldn’t be taken to the point where diversity is sacrificed for simple uniformity.
Nature penalizes monocultures in biological systems. Monocultures are devastated by disease and predators because they have insufficient diversity to resist. The irish potato famine, the emerald ash borer, and the decimation of the Aztecs by smallpox are all examples of what happens when diversity is not present. Nature naturally promotes diversity to ensure a robust population.
We all practice diversity in our everyday lives. Diversity of motor vehicles, for instance supports fitness for purpose—a Camero, is not useful for hauling dozens of large boxes of materials. For that, we use a truck. However, for one person to get from point A to point B in an economical fashion, a truck is not the best choice. It might be cheaper and require less training to use the same vehicle for everything, but there are advantages to diversity. Or tableware—we have (perhaps) too many forks and spoon types in a formal placesetting, but try eating soup with a fork and you discover that some differentiation is useful!
In computing, competition has resulted in advances in hardware and software design. Choice among products has kept different approaches moving forward. Competition for research awards from DARPA and NSF has encouraged deeper thought and more focused proposals (and resultant development). Diversity in operating systems and programming languages brought many advancements in the era 1950-2000. However, expenses and attempts to cut staff have led to widespread homogenization of OS, applications, and languages over approximately the last decade.
Despite the many clear benefits of promoting diversity, too many organizations have adopted practices that prevent diversity of software and computing platforms. For example, the OMB/DoD Common Desktop initiative is one example where the government is steering personnel towards a monoculture that is more maintainable day-to-day, but which is probably more vulnerable to zero-day attacks and malware.
Disadvantages of homogeneity:
Advantages of homogeneity:
Disadvantages of heterogeneity:
Advantages of heterogeneity:
Reviewing the above lists makes clear that entities concerned with self-continuation and operation will promote diversity, despite some extra expense and effort. The potential disadvantages of diversity are all things that can be countered with planning or budget. The downsides of monocultures, however, cannot be so easily addressed.
Dan Geer wrote an interesting article for Queue Magazine about diversity, recently. It is worth a read.
The simplified conclusion: diversity is good to have.
[tags]complexity,security,virtualization,microkernels[/tags]
One of the key properties that works against strong security is complexity. Complexity poses problems in a number of ways. The more complexity in an operating system, for instance, the more difficult it is for those writing and maintaining it to understand how it will behave under extreme circumstances. Complexity makes it difficult to understand what is needed, and thus to write fault-free code. Complex systems are more difficult to test and prove properties about. Complex systems are more difficult to properly patch when faults are found, usually because of the difficulty in ensuring that there are no side-effects. Complex systems can have backdoors and trojan code implanted that is more difficult to find because of complexity. Complex operations tend to have more failure modes. Complex operations may also have longer windows where race conditions can be exploited. Complex code also tends to be bigger than simple code, and that means more opportunity for accidents, omissions and manifestation of code errors.
It is simple that complexity creates problems.
Saltzer and Schroeder identified it in their 1972 paper in CACM. They referred to “economy of mechanism” as their #1 design principle for secure systems.
Some of the biggest problems we have now in security (and arguably, computing) are caused by “feature creep” as we continue to expand systems to add new features. Yes, those new features add new capabilities, but often the additions are foisted off on everyone whether they want them or not. Thus, everyone has to suffer the consequences of the next exapnded release of Linux, Windows (Vista), Oracle, and so on. Many of the new features are there as legitimate improvements for everyone, but some are of interest to only a minority of users, and others are simply there because the designers thought they might be nifty. And besides, why would someone upgrade unless there were lots of new features?
Of course, this has secondary effects on complexity in addition to the obvious complexity of a system with new features. One example has to do with backwards compatibility. Because customers are unlikely to upgrade to the new, improved product if it means they have to throw out their old applications and data, the software producers need to provide extra code for compatibility with legacy systems. This is not often straight-forward—it adds new complexity.
Another form of complexity has to do with hardware changes. The increase in software complexity has been one motivating factor for hardware designers, and has been for quite some time. Back in the 1960s when systems began to support time sharing, virtual memory became a necessity, and the hardware mechanisms for page and segment tables needed to be designed into systems to maintain reasonable performance. Now we have systems with more and more processes running in the background to support the extra complexity of our systems, so designers are adding extra processing cores and support for process scheduling.
Yet another form of complexity is involved with the user interface. The typical user (and especially the support personnel) now have to master many new options and features, and understand all of their interactions. This is increasingly difficult for someone of even above-average ability. It is no wonder that the average home user has myriad problems using their systems!
Of course, the security implications of all this complexity have been obvious for some time. Rather than address the problem head-on by reducing the complexity and changing development methods (e.g., use safer tools and systems, with more formal design), we have recently seen a trend towards virtualization. The idea is that we confine our systems (operating systems, web services, database, etc) in a virtual environment supported by an underlying hypervisor. If the code breaks…or someone breaks it…the virtualization contains the problems. At least, in theory. And now we have vendors providing chipsets with even more complicated instruction sets to support the approach. But this is simply adding yet more complexity. And that can’t be good in the long run. Already attacks have been formulated to take advantage of these added “features.”
We lose many things as we make systems more complex. Besides security and correctness, we also end up paying for resources we don’t use. And we are also paying for power and cooling for chips that are probably more powerful than we really need. If our software systems weren’t doing so much, we wouldn’t need quite so much power “under the hood” in the hardware.
Although one example is hardly proof of this general proposition, consider the results presented in 86 Mac Plus Vs. 07 AMD DualCore. A 21-year old system beat a current top-of-the-line system on the majority of a set of operations that a typical user might perform during a work session. On your current system, do a “ps” or run the task manager. How many of those processes are really contributing to the tasks you want to carry out? Look at the memory in use—how much of what is in use is really needed for the tasks you want to carry out?
Perhaps I can be accused of being a reactionary ( a nice word meaning “old fart:”), but I remember running Unix in 32K of memory. I wrote my first full-fledged operating system with processes, a file system, network and communication drivers, all in 40K. I remember the community’s efforts in the 1980s and early 1990s to build microkernels. I remember the concept of RISC having a profound impact on the field as people saw how much faster a chip could be if it didn’t need to support complexity in the instruction set. How did we get from there to here?
Perhaps the time is nearly right to have another revolution of minimalism. We have people developing low-power chips and tiny operating systems for sensor-based applications. Perhaps they can show the rest of us some old ideas made new.
And for security? Well, I’ve been trying for several years to build a system (Poly^2) that minimalizes the OS to provide increased security. To date, I haven’t had much luck in getting sufficient funding to really construct a proper prototype; I currently have some funding from NSF to build a minimal version, but the funding won’t allow anything close to a real implementation. What I’m trying to show is too contrary to conventional wisdom. It isn’t of interest to the software or hardware vendors because it is so contrary to their business models, and the idea is so foreign to most of the reviewers at funding agencies who are used to build ever more complex systems.
Imagine a system with several dozen (or hundred) processor cores. Do we need process scheduling and switching support if we have a core for each active process? Do we need virtual memory support if we have a few gigabytes of memory available per core? Back in the 1960s we couldn’t imagine such a system, and no nation or company could afford to build one. But now that wouldn’t even be particularly expensive compared to many modern systems. How much simpler, faster, and more secure would such a system be? In 5 years we may be able to buy such a system on a single chip—will we be ready to use it, or will we still be chasing 200 million line operating systems down virtual rat holes?
So, I challenge my (few) readers to think about minimalism. If we reduce the complexity of our systems what might we accomplish? What might we achieve if we threw out the current designs and started over from a new beginning and with our current knowledge and capabilities?
[Small typo fixed 6/21—thanks cfr]
Copyright © 2007 by E. H. Spafford
[posted with ecto]
[tags]phishing, web redirection[/tags]
Jim Horning suggested a topic to me a few weeks ago as a result of some email I sent him.
First, as background, consider that phishing and related frauds are increasingly frequent criminal activities on the WWW. The basic mechanism is to fool someone into visiting a WWW page that looks like it belongs to a legitimate organization with which the user does business. The page has fields requesting sensitive information from the user, which is then used by the criminals to commit credit card fraud, bank fraud or identity theft.
Increasingly, we have seen that phishing email and sites are also set up to insert malware into susceptible hosts. IE on Windows is the prime target, but attacks are out there for many different browsers and systems. The malware that is dropped can be bot clients, screen scrapers (to capture keystrokes at legitimate pages), and html injectors (to modify legitimate pages to ask for additional information). It is important to try to keep from getting any of this malware onto your system. One aspect of this is to be careful clicking on URLs in your email, even if they seem to come from trusted sources because email can be spoofed, and mail can be sent by bots on known machines.
How do you check a URL? Well, there are some programs that help, but the low-tech way is to look at the raw text of a URL before you visit it, to ensure that it references the site and domain you expected.
But consider the case of short-cut URLs. There are many sites out there offering variations on this concept, with the two I have seen used most often being “TinyURL” and “SnipURL”. The idea is that if you have a very long URL that may get broken when sent in email, or that is simply too difficult to remember, you submit it to one of these services and you get a shortened URL back. With some services, you can even suggest a nickname. So, for example, short links to the top level of my blog are <http://tinyurl.com/2geym5>, <http://snipurl.com/1ms17> and <http://snurl.com/spafblog>.
So far, this is really helpful. As someone who has had URLs mangled in email, I like this functionality.
But now, let’s look at the dark side. If Jim gets email that looks like it is from me, with a message that says “Hey Jim, get a load of this!” with one of these short URLs, he cannot tell by looking at the URL whether it points somewhere safe or not. If he visits it, it could be a site that is dangerous to visit (Well, most URLs I send out are dangerous in one way or another, but I mean dangerous to his computer. ). The folks at TinyURL have tried to address this by adding a feature so that if you visit <http://preview.tinyurl.com/2geym5> you will get a preview of what the URL resolves to; you can set this (with cookies) as your default. That helps some.
But now step deeper into paranoia. Suppose one of these sites was founded by fraudsters with the intent of luring people into using it. Or the site gets acquired by fraudsters, or hijacked. The code could be changed so that every time someone visits one of these URLs, some code at the redirect site determines the requesting browser, captures some information about the end system, then injects some malicious javacode or ActiveX before passing the connection to the “real” site. Done correctly, this would result in largely transparent compromise of the user system. According to the SnipURL statistics page, as of midnight on May 30th there have been nearly a billion clicks on their shortened URLs. That’s a lot of potential compromises!
Of course, one of the factors to make this kind of attack work is for the victim to be running a vulnerable browser. Unfortunately, there have been many vulnerabilities found for both IE and Firefox, as well as some of the less well-known browsers. With users seeking more functionality in their browsers, and web designers seeking more latitude in what they deliver, we are likely to continue to see browser exploits. Thus, there is likely to be enough of a vulnerable population to make this worthwhile. (And what browser are you using to read this with?)
I should make it clear that I am not suggesting that any of these services really are being used maliciously or for purposes of fraud. I am a happy and frequent user of both TinyURL and SnipURL myself. I have no reason to suspect anything untoward from those sites, and I certainly don’t mean to suggest anything sinister. (But note that neither can I offer any assurances about their motives, coding, or conduct.) Caveat emptor.
This post is simply intended as commentary on security practices. Thinking about security means looking more deeply into possible attack vectors. And one of the best ways to commit such attacks is to habituate people into believing something is safe, then exploiting that implicit trust relationship for bad purposes.
Hmm, reminds me of a woman I used to date. She wasn’t what she appeared, either…. But that’s a story for a different post.
[posted with ecto]
[tags]viruses,OpenOffice,Word,Microsoft,Office,Powerpoint,Excel[/tags]
In my last post, I ranted about a government site making documents available only in Word. A few people have said to me “Get over it—use OpenOffice instead of the Microsoft products.” The problem is that those are potentially dangerous too—there is too much functionality (some of it may be undocumented, too) in Word (and Office) documents.
Now, we have a virus specific to OpenOffice. We’ve had viruses that run in emulators, too. Trying to be compatible with something fundamentally flawed is not a security solution. That’s also my objection to virtualization as a “solution” to malware.
I don’t mean to be unduly pejorative, but as the saying goes, even if you put lipstick on a pig, it is still a pig.
Word and the other Office components are useful programs, but if MS really cared about security, they would include a transport encoding that didn’t include macros and potentially executable attachments—and encourage its use! RTF is probably that encoding for text documents, but it is not obvious to the average user that it should be used instead of .doc format for exchanging files. And what is there for Excel, Powerpoint, etc?
