Tuesday, April 30, 2013

Fact or Fiction: Is Huawei a Risk to Critical Infrastructure?

By Gunter Ollmann - @gollmann

How much of a risk does a company like Huawei or ZTE pose to U.S. national security? It’s a question that’s been on many peoples lips for a good year now. Last year the U.S. House of Representatives Permanent Select Committee on Intelligence warned American companies to “use another vendor”, and earlier in that year the French senator and former defense secretary Jean-Marie Bockel recommended a “total prohibition in Europe of core routers and other sensitive IT equipment coming from China.” In parallel discussions, the United Kingdom, Australia and New Zealand (to name a few) have restricted how Huawei operates within their borders.

Last week Eric Xu – executive vice-president and one of the triumvirate jointly running Huawei – stunned analysts when he told them that Huawei was “not interested in the U.S. market any more.”

Much of the analysis has previously focused upon Huawei's sizable and influential position as the world’s second largest manufacturer of network routers and switching technology – a critical ingredient for making the Internet and modern telecommunications work – and the fact that it is unclear as to how much influence (or penetration) the Chinese government has in the company and its products. The fear is that at any point now or in the future, Chinese military leaders could intercept or disrupt critical telecommunications infrastructure – either as a means of aggressive statecraft or as a component of cyber warfare.

As someone who's spent many years working with the majority of the world's largest telecommunication companies, ISP's, and cable providers, I've been able to observe firsthand the pressure being placed upon these critical infrastructure organizations to seek alternative vendors and/or replace any existing Huawei equipment they may already have deployed. In response, many of the senior technical management and engineers at these organizations have reached out to me and to IOActive to find out how true these rumors are. I use the term “rumor” because, while reports have been published by various government agencies, they’re woefully lacking in technical details. You may have also seen François Quentin (chairman of the board of Huawei France) claiming that the company is a victim of “rumors”.

In the public technical arena, there are relatively few bugs and vulnerabilities being disclosed in Huawei equipment. For example, if you search for CVE indexed vulnerabilities you’ll uncover very few. Compared to the likes of Cisco, Juniper, Nokia, and most of the other major players in routing and switching technology, the number of public disclosures is miniscule. But this is likely due to a few of the following reasons:
  • The important Huawei equipment isn't generally the kind of stuff that security researchers can purchase off Ebay and poke around with at home for a few hours in a quest to uncover new bugs. They're generally big-ticket items. (This is the same reason why you’ll see very few bugs publicly disclosed in Cisco’s or Nokia’s big ISP-level routers and switches).
  • Up until recently, despite Huawei being such a big player internationally, they haven't been perceived as such to the English-speaking security researcher community – so have traditionally garnered little interest from bug hunters.
  • Most of the time when bugs are found and exploitable vulnerabilities are discovered, they occur during a paid-for penetration test or security assessment, and therefore those findings belong to the organization that commissioned the consulting work – and are unlikely to be publicly disclosed.
  • Remotely exploitable vulnerabilities that are found in Huawei equipment by independent security researchers are extremely valuable to various (international) government agencies. Any vulnerability that could allow someone to penetrate or eavesdrop at an international telecommunications carrier-level is worth big bucks and will be quickly gobbled up. And of course any vulnerability sold to such a government agency most certainly isn't going to be disclosed to the vulnerable vendor – whether that be Huawei, Cisco, Juniper, Nokia, or whatever.

What does IOActive know of bugs and exploitable vulnerabilities within Huawei’s range of equipment? Quite a bit obviously – since we've been working to secure many of the telecommunications companies around the world that have Huawei’s top-end equipment deployed. It’s obviously not for me to disclose vulnerabilities that were uncovered on the dime of an IOActive client, however many of the vulnerabilities we've uncovered during tests have given great pause to our clients as remedies are sought.

Interesting enough, the majority of those vulnerabilities were encountered using standard network discovery techniques - which to my mind is just scratching the surface of things. However, based upon what’s been disclosed in these afore mentioned government reports over the last year, that was probably their level of scrutinization too. Digging deeper in to the systems reveals more interesting security woes.

Given IOActive’s expertise history and proven capability of hardware hacking, I’m certain that we’d be able to uncover a whole host of different and more significant security weaknesses in these critical infrastructure components for clients that needed that level of work done. To date IOActive the focus has be on in-situ analysis – typically assessing the security and integrity of core infrastructure components within live telco environments.

I've heard several senior folks talk of their fears that even with full access to the source code that that wouldn't be enough to verify the integrity of Chinese network infrastructure devices. For a skillful opponent, that is probably so, because they could simply hide the backdoors and secret keys in the microcode of the devices semiconductor chips.

Unfortunately for organizations that think they can hide such critical flaws or backdoors at the silicon layer, I've got a surprise for you. IOActive already has the capability strip away the layers of logic within even the most advanced and secure microprocessor technologies out there and recover the code and secrets that have been embedded within the silicon itself.

So, I’d offer a challenge out there to the various critical infrastructure providers, government agencies, and to manufacturers such as Huawei themselves – let IOActive sort out the facts from the multitude of rumors. Everything you've probably been reading is hearsay.

Who else but IOActive can assess the security and integrity of a technology down through the layers – from the application, to the drivers, to the OS, to the firmware, to the hardware and finally down to the silicon of the microprocessors themselves? Exciting times!

-- Gunter Ollmann, CTO IOActive Inc.

Thursday, April 18, 2013

InfoSec Europe 2013 - Security on Tap

By Gunter Ollmann, @gollmann

It's that time of the year again as Europe's largest and most prestigious information security conference "Infosecurity Europe" gets ready to kick off next week at Earls Court, London, UK.

This year's 18th annual security gathering features over 350 exhibitors, but you won't find IOActive on the floor of the conference center. Oh no, we're pulling out all the stops and have picked a quieter and more exclusive location to conduct our business just around the corner. After all, why would you want to discuss confidential security issues on a floor with 12,500 other folks?

We all know what these conferences are like. We psych ourselves up for a couple of days for shuffling from one booth to the next, avoiding eye contact with the glammed-up booth-babes working their magic on blah-blah's vendor booth - who's only mission in life is to scan your badge so that a far-off marketing team can spam you for the next 6 months with updates about a product you had no interest in - who you unfortunately allowed to scan your badge because they were giving away an interesting  foam boomerang (that probably cost 20 pence) which you thought one of your kids might like as recompense for the guilt you're feeling at having to be away from home one evening so you could see all of what the conference had to offer.

Well fret no more, IOActive have come to save the day!

After you've grown tired and wary of the endless shuffling, avoided eye-contact for as long as possible, grabbed enough swag to keep the neighbors grandchildren happy for a decade's worth of birthdays, and the imminent prospect of standing in queues for over priced tasteless coffee and tea has made your eyes roll further in to the back of your skull one last time, come visit IOActive down the street at the pub we've taken over! Yes, that's right, IOActive crew have taken hostage a pub and we're inviting you and a select bunch of our VIP's to come join us in a more relaxed and conducive business environment.

I hear tell that the "Security on Tap" will include a range of fine ales, food and other refreshments, and that the decibel level should be a good 50dB lower than Earls Court Conference Center. A little birdy also mentioned that there may be a whisky tasting going on at some point too. Oh, and there'll be a bunch of us IOActive folks there too. Chris Valasek and I, along with some of our top UK-based consultants will be there talk about the latest security threats and evil hackers. I think there'll be some sales folks there too - but don't worry, we'll make sure that their badge readers don't work.

If you'd like to join us for drinks, refreshments and intelligent conversation in a venue that's comfortable and won't have you going hoarse (apparently "horse" is bad these days) - you're cordially invited to join us at the Courtfield Pub (187 Earls Court Road, Earls Court, London, SW5 9AN). We'll be there Tuesday and Wednesday (April 23rd & 24th) between 10:00 and 17:00.

To prevent the prospect of having to queue to get in, I'd ask you to quickly RSVP on the page we've crafted specifically for the Infosec event. Go on, RSVP HERE!

-- Gunter Ollmann, CTO IOActive

Tuesday, April 16, 2013

Can GDB's List Source Code Be Used for Evil Purposes?

By Alejandro Hernández @nitr0usmx

One day while debugging an ELF executable with the GNU Debugger (GDB), I asked myself, "How does GDB know which file to read when you use the list command?" (For the uninformed, the list command prints a specified number of lines from a source code file -— ten lines is the default.)
Source code filenames are contained in the metadata of an ELF executable (in the .debug_line section, to be exact). When you use the list command, GDB will open(), read(), and display the file contents if and only if GDB has the permissions needed to read the source file. 
The following is a simple trick where you can use GDB as a trampoline to read a file which originally you don’t have enough permission to read. This trick could also be helpful in a binary capture-the-flag (CTF) or reverse engineering challenge.
Here are the steps:

1. Compile 'foo.c' with the GNU Compiler (GCC) using the -ggdb flag.

2. Open the resulting ELF executable with GDB and the list command to read its source code as shown in the following screen shot:

3. Make a copy of ‘foo.c’ and call it ‘_etc_shadow.c’, so that this name is hardcoded within the internal metadata structures of the compiled ELF executable as in the following screen shot.

4. Open the executable with your preferred hex editor (I used HT Editor because it supports the ELF file format) and replace ‘_etc_shadow.c’ with ‘/etc/shadow’ (don't forget the NULL character at the end of the string) the first two times it appears.

5. Evidently, it won't work unless you have sufficient user privileges, otherwise GDB won’t be able to read /etc/shadow.

6. If you trace the open() syscall calls executed by GBD:
 ($strace -e open gdb ./_etc_shadow) 
you can see that it returns -1 (EACCES) because of insufficient permissions.

7. Now imagine that for some reason GDB is a privileged command (the SUID (Set User ID) bit in the permissions is enabled). Opening our modified ELF file with GDB, it would be possible to read the contents of ‘/etc/shadow’ because the gdb command would be executed with root privileges.

8. Imagine another hypothetical scenario: a hardened development (or CTF) server that has been configured with granular privileges using a tool such as Sudo to allow certain commands to be executed. (To be honest I have never seen a scenario like this before, but it’s an example worth considering to illustrate how this attack might evolve).

9. You cannot display the contents of ‘/etc/shadow’ by using the cat command because /bin/cat is an unauthorized command in our configuration. However, the gdb command has been authorized and therefore has the rights needed to display the source file (/etc/shadow):


Taking advantage of this GDB feature and mixing it with other techniques could make a more sophisticated attack possible. Use your imagination.

Do you have other ideas how this could be used as an attack vector, either by itself or if combined with other techniques? Let me know.

Wednesday, April 10, 2013

What Would MacGyver Do?

By Sofiane Talmat @_Sud0

"The great thing about a map: it gets you in and out of places in a lot different ways." - MacGyver 

When I was young I was a big fan of the American TV show, MacGyver. Every week I tuned in to see how MacGyver would build some truly incredible things with very basic and unexpected materials — even if some of his solutions were hard to believe. For example, in one episode MacGyver built a futuristic motorized heat-seeking gun using only a set of batteries, an electric mixer, a rubber band, a serving cart, and half a suit of armor.

From that time I always kept the “What would MacGyver do?” spirit in my thinking. On the other hand I think I was “destined” to be an IT guy, and particularly in the security field, where we don’t have quite the same variety of materials to craft our solutions. 

But the “What would MacGyver do?” frame of mind helped me figure out a simple way to completely “own” a network environment in a MacGyver sort of way using just a small set of steps, including:

  • Exploiting a bad use of tools.
  • A small piece of social engineering.
  • Some creativity.
  • A small number of manual configuration changes..

Tuesday, April 2, 2013

Spotting Fake Chips in the Supply Chain

By Christopher Tarnovsky @semiconduktor & Gunter Ollmann @gollmann

In the information security world we tend to focus upon vulnerabilities that affect the application and network architecture layers of the enterprise and, every so often, some notable physical devices. Through various interrogatory methods we can typically uncover any vulnerabilities that may be present and, through discussion with the affected business units, derive a relative statement of risk to the business as a whole.

An area of business rarely dissected from an information security perspective however is the supply chain. For manufacturing companies and industrial suppliers, nothing is more critical to their continued business success than maintaining the integrity and reliability of their supply chain. For some industries – such as computer assembly or truck fabrication facilities – even the smallest hiccup in their just-in-time ordering system can result in entire assembly lines being gummed up and product not being rolled out the front door.