Has Tor Been Compromised?

There's speculation that the FBI is responsible for an exploit that compromised the Tor anonymity service. Note that Tor nodes Browser Bundles installed or updated after June 26 are secure.

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Posted on August 6, 2013 at 1:42 PM • 51 Comments

Comments

Gweihir • August 6, 2013 1:59 PM

Also note that mozilla classified the vulnerability as "critical" and everybody caught did not update for more than 4 weeks and was running Windows. I have some issues with calling this a zero-day vulnerability, as it and the patch for it was out there for 4 weeks. Sure, the person that found the problem did not have an exploit, but only a crash (i.e. injection of invalid code) that still strongly suggests that working exploit code could be injected instead. So lets call it a "zero-day if you have no clue".

Still, knowing that it takes the NSA and accomplices about 4 weeks from a reported potential vulnerability to a deployed attack is interesting. I would suggest that this means checking for updates at least once a week is mandatory.

There is a rumor that the people caught also used the same browser for Tor and normal browsing, but my take from the analysis is that this is wrong and the exploit just contacted an external server directly while the Tor session was still running.

secret police • August 6, 2013 2:15 PM

FBI contacted SAICs to deploy this exploit. It didn't just affect illegal websites it was present on Tormail and even freedom activist forums. The exploit phoned home your MAC and location which wouldn't have happened if you were using TBB in a VM or firewalled behind NAT with local IP.

Just because this only affected Windows doesn't mean the next secret police exploit won't target the linux kernel. If you want to whistleblow should look into Jondo live CD with it's install of mixminion Type III Anonymous remailer instead of trusting Tor browser devs who insanely activated javascript by default allowing this to happen.

Daniel • August 6, 2013 2:16 PM

There is simply so much we do not know about this...

Just because the vulnerability was reported to Mozilla on Day X does not mean that was the day the FBI or whoever first became aware of it. They could have been exploiting it for months in the wild and only after it had been identified by a third party and patched that they finally arrested the guy because the utility of that exploit had become less valuable to them.

There is also an on-going debate as to whether this was really a child porn hit or whether the child porn was just a cover for the take down of Tormail, which apparently has been quite popular with critics of the US Government.

One thing for sure is that Tor's reputation is badly damaged. Because if the USA can do this to Tor there is nothing stopping the security services of any of the other nations from doing it too. It's not as if zero day exploits are cost prohibitive to purchase on the open market when governments interests are at stake.

Bob • August 6, 2013 2:18 PM

I will repeat a past comment: Bruce has rightly drawn attention to the human and social elements of security. Let's ask ourselves if the NSA, obsessed with getting access to *everything* would let potentially the highest value traffic - people who opt into Tor to hide something - pass them by. I just think there is now way they would. Which logically implies they must have either intercepts or exploits on a regular basis. With the billions of dollars and thousands of employees it's just crazy to think that Tor is secure against the NSA. Maybe against everyone else, maybe, but that's it.

JeffH • August 6, 2013 3:00 PM

@secret police "If you want to whistleblow should look into Jondo live CD with it's install of mixminion Type III Anonymous remailer instead of trusting Tor browser devs who insanely activated javascript by default allowing this to happen."

I'm always curious about these sorts of posts. How would anyone know with confidence that this provides real anonymity, or any kind of security? In the crypto world, we are used to using algorithms that are well known, publicly available, preferably that large numbers of experts have looked at over the course of years, and we still don't fully trust them even then; there's always that little voice saying 'we may not know everything, don't rely on this as a single point of failure'.

Where's the equivalent for anonymous or secure systems like this? Why should anyone treat this any differently to any other person claiming 'this stuff is secure'?

Don't get me wrong - I applaud all the attempts to make these kinds of systems available, but it still doesn't mean I'd trust them without a lot of evidence & respected figures stating 'we've had a good look at this, it seems ok'. I'd love to see more efforts on making these kinds of things more publicly visible & available. Tor is a good start - can anyone do better?

hmm true • August 6, 2013 3:35 PM

Mixminion uses anonymous padding and time delay mixmasters, and has been in use since 2002 its not new crypto engineering. It also uses PGP/nym servers that have been around for decades.The Germann Privacy Foundation and CCC both recommended Jondo, Tor, Freenet and I2p.

The Jondo live CD is open source, so is Tails, Liberte Linux and torproject but you could always build your own system from scratch using hardened gentoo, another project that has been around for years. What hasn't been around is Tor's browser bundle which they tried to make Windows idiot friendly and this is the result. There shouldn't have even been a win release, if you want Tor for win use a VM or live CD with free software.

Personally I wouldn't run any graphical desktop if attempting strong pseudoanonymity due to the research of Loic Duflot consistently finding holes in Xorg/Xfce/Unity and any other X implementation but unfortunately its all there is unless you are a neckbeard and familiar with bsd or linux command line.

Who knows if the. iso you download is actually built from the source too, hardly anybody bothers to check signatures according to Tails research.

Michael Lynn • August 6, 2013 3:37 PM

@Gweihir:
"Still, knowing that it takes the NSA and accomplices about 4 weeks from a reported potential vulnerability to a deployed attack is interesting."

I find it more likely that they noticed their 0-day had been patched and decided to squeeze every last bit of usefulness as they could out of it. Thats the only reason I see for them being willing to do such a public operation that revealed such capabilities.

Jim • August 6, 2013 3:41 PM

"Note that Tor nodes installed or updated after June 26 are secure." Note that this is NOT a security problem with Tor routing nodes or exit nodes. It's a client-side problem in the Tor browser bundle, which was exploited by placing malicious Javascript on a specific popular Tor website.

Carpe • August 6, 2013 3:42 PM

All traces are actually largely pointing to SAIC. (and most of us know which two-three letters they work with the most)

Critic • August 6, 2013 3:51 PM

Maybe the FBI is responsible for the exploit, but how did they get the exploit code onto the servers in the first place? Were the compromised servers all running the same software, or did law enforcement find and compromise the physical servers, perhaps with help from the NSA?

Will the FBI engage in "parallel construction" to conceal what really happened?

Critic • August 6, 2013 3:55 PM

"Note that Tor nodes installed or updated after June 26 are secure."

Please note this was a browser exploit. TOR nodes themselves aren't affected. How those were compromised has not been disclosed.

secret police • August 6, 2013 4:13 PM

The timeline was around 29Jul they arrested the Freedom Hosting admin, and all sites went down. 2 days later they went back up hosting the exploit.

As for replacing Tor, GnuNet is an ambitious p2p project that offers stronger anonymity to timing analysis and better decentalization but still beta software

unknown.soldier • August 6, 2013 4:16 PM

Bob • August 6, 2013 2:18 PM
I will repeat a past comment: Bruce has rightly drawn attention to the human and social elements of security. Let's ask ourselves if the NSA, obsessed with getting access to *everything* would let potentially the highest value traffic - people who opt into Tor to hide something - pass them by. I just think there is now way they would. Which logically implies they must have either intercepts or exploits on a regular basis. With the billions of dollars and thousands of employees it's just crazy to think that Tor is secure against the NSA. Maybe against everyone else, maybe, but that's it.

I could not agree more. I have worked on these systems and our goal there was to aid dissidents in China and the ME, with secondary goals of creating a media ruckus to bring journalistic attention to these problems.... and help lay a foundation for people in the "free" world when they would need it. [A more quiet agenda.]

Point being: while I am sure there are a lot of real scumbags using these systems, fact is there are also "dissidents". Enemies of the state. Freedom pioneers. Human rights activists.

And then you have your foreign spies on shore. You have your Mannings and Snowdens of more anonymous stripes. You have your journalists working with leakers. You have your genuine - very, very rare - moles.

And you probably have your terrorists.

Facebook? Twitter? Uhm, no.

They know this, be they the PLA of China, the morality police of Saudi Arabia, or the FBI/NSA/CIA of the USofA.


unknown.soldier • August 6, 2013 4:30 PM

Critic • August 6, 2013 3:51 PM
Maybe the FBI is responsible for the exploit, but how did they get the exploit code onto the servers in the first place? Were the compromised servers all running the same software, or did law enforcement find and compromise the physical servers, perhaps with help from the NSA?
Will the FBI engage in "parallel construction" to conceal what really happened?

The FBI is capable of anything. The infamous cointelpro was FBI. It wasn't the CIA or NSA who wiretapped the Senate through the thirties to seventies, it was the FBI. Great book on the FBI: "Enemies", covers a lot of these matters and clears up that the FBI is first and foremost **an intelligence agency**. Contrary to popular television and tv shows -- contrary to a lot of their more public work.

FBI runs counterintelligence within the US.

Anything is possible in what was down. They have run all sorts of criminals and criminal organizations as effective honeypots.

This sort of thing is far too widespread to have ever been kept completely secret from the public eye -- look at the Bulger case, for one instance of so many others. They ran Bulger, admit it, and what is hilarious is Bulger is the one saying they did not (yet while also claiming he had immunity -- from everything).

Another one of my favorites is a mafia hitman they ran in the sixties. For real. These are guys that seriously fucked with Martin Luther King Jr of all people.

Sure, many of them are probably honest cops with good hearts. Same thing can be said of a lot of cops in Vietnam or North Korea.

The way the world is. Sad, really. Some even would say it is run by Satan.


unknown.soldier • August 6, 2013 4:39 PM

Don't get me wrong - I applaud all the attempts to make these kinds of systems available, but it still doesn't mean I'd trust them without a lot of evidence & respected figures stating 'we've had a good look at this, it seems ok'. I'd love to see more efforts on making these kinds of things more publicly visible & available. Tor is a good start - can anyone do better?

I have worked on some of these systems. **You can trust me**.

Fact is, I would not trust any singular system, and even for systems where I know the authors - what do I really know about such super paranoid people? They could work for anyone for all I know. For all anyone knows.

Beyond that, there will be security vulnerabilities in any software. The feds (of any sizeable nation) have teams and teams of people looking for vulnerabilities day and night.

Only time we use these systems our own selves is when we are saying **nothing**. Let them work to get to nothing. Makes it far more pleasing.

("We" anyone I know who have made such systems. There are some peer groups in there.)

*IF* I were ever trying to hide any serious communication, I would never use the internet, or at least, not my own system.

The opposite is true: you assume surveillance 24/7, and unknown technology beyond what you can imagine or understand is possible. Great case in point: When Russia hid a bug in the American Seal in the Moscow embassy. Previously unknown tech, alien. They only got it because they found evidence the room was somehow compromised. The great nations couldn't have predicted that. They do not know what they do not know.

What kind of chance does a regular Joe then have?

Conversely, you can create your own effective language. This is what is said Al Qaeda does. Bruce has posted on some of these languages, some prison languages are good examples.

Only real way to have any level of assurance, probably.

G van Grijnen • August 6, 2013 5:18 PM

@JeffH,

"How would anyone know with confidence that this provides real anonymity, or any kind of security?"

No one could know this.

And people who claim this are just deceiving themselves.

Telephone lines are insecure because they are monitored and software to protect us from monitoring is insecure because software inherently contains vulnerabilities.

And we can never be sure if those vulnerabilities are discovered and used against us.

Telephone lines are simply not suitable for sharing secrets.

But if I was forced to communicate my secrets over a telephone line, I would try to blend in with the crowd and hide my messages in plain sight.

I would shun encryption like the plague, because it would stick out like a sore thumb for every traffic analyst to see.

Brian Lee • August 6, 2013 7:09 PM

Hiding in plain sight is dangerously close to the idea of security through obscurity. If someone is analyzing your traffic to the point of examining content type though, you can bet that they are also looking at the content itself, the destination(s), the nodes in the communication patterns, etc.

However, for the paranoid amongst us, hiding genuinely encrypted data by encoding it in other formats is an interesting one. I could imagine a secure channel being disguised as spam e-mails with the actual encrypted data being encoded into images, either as attachments or in a link to a hosting site of some sort.

Of course, you need to go further than that. You must also disguise your traffic pattern. I am interested in knowing if Tor is of any use there or if the use of a Tor node is equivalent to trying to hide in a dark room while holding a lit match?

hmclean • August 6, 2013 7:34 PM

Please note this was a browser exploit. TOR nodes themselves aren't affected.
This might (assuming it's not disinformation) indicate that the Tor network itself is relatively secure--if the NSA had compromised the network, they wouldn't need to make browsers contact their server to figure out people's IP addresses.

Dirk Praet • August 6, 2013 7:41 PM

As some commentors have already pointed out, Tor itself has not been compromised. This exploit specifically targets FF 17, which is part of Tor browser bundles (TBB) released before June 26th and for the Windows platform only . All .onion sites and other services hosted on the Freedom Hosting platform however need to be considered fully compromised.

My personal analysis is that the FBI (or other TLA) has sacrificed an expendable pawn in the course of some ongoing sting operation. Surely, they must have known that the injected Magneto code would be found out about in no time. That said, it is highly probable that those responsible for the operation still dispose of a series of additional FF 0-days and other exploits that may or may not impact Tor usage in much more dangerous ways.

As usual, it is wise to update/patch Tor (or any other software) frequently, configure and use it as per best practices guidelines and never ever put exclusive trust in it for life or death matters. Tor is just one knife out of an entire drawer of security/privacy/anonimity tools. Learn to use them all, and use them wisely. Also remember that technical tools alone won't cut it and that overall OPSEC is even more important. For those interested, take a look at thegrugq's excellent "OPSEC for Hackers: because jail is for wuftpd" at https://www.youtube.com/watch?v=9XaYdCdwiWU .

Daniel • August 6, 2013 9:44 PM

I strongly disagree with this idea that "Tor itself hasn't been compromised." While that is true in a technical sense it is false in a holistic sense. Many unsophisticated people put their trust in the TBB-Tor Browser Bundle. Tor encouraged this behavior, indeed they went so far as to turn Javascript on by default in TBB order to make browsing the web easier for these unsophisticated folks. And a few of these folks got in over their heads and whether maliciously or simply foolishly visited sites they shouldn't have. While I am not one of them, I think such victims have every right to feel betrayed. Tor put their name and their reputation on the line when they labeled it the Tor Browser Bundle and encouraged folks to use it. It is disingenuous to say then that Tor has not been hacked.

When TBB was first proposed there were people in the Tor community who opposed creating the bundle because they felt that it was too risky but their objections were overruled under the logic that Tor needed a larger user base and the concerns these Negative Nancies raised were dismissed as airy hypotheticals. Well, those naysayers were proven right. The gun might have been Firefox and the FBI might have been the triggerman but it was Tor and Tor alone that gathered all the fish in the barrel.

Guillaume • August 6, 2013 10:12 PM

@Gweihir : Maybe the NSA knew about the vulnerability long before it was made public (they do their own security research). The 4 week time-to-exploit is not a reliable metric.

averros • August 7, 2013 1:00 AM

"Hiding in plain sight is dangerously close to the idea of security through obscurity."

It worked nicely for generations of Soviet people. Despite the massive network of informants (KGB once employed over a million people), massive wiretapping, tight control of copiers and typewriters, and no legal restraints whatsoever, it didn't manage to stem the propagation of the ideas (first by the small groups of dissidents, later by the word of mouth and samizdat (clandestine reprinting)) which fruited in the revolution of 1989-91 which destroyed the Soviet Union.

The main reason why this tactic worked is that no matter how powerful, the secret police is still a small fraction of population, and its agents are more concerned with their own internal political struggles than enforcing the will of their political masters (working for NKVD/KGB was the most dangerous occupation... quite a lot of them was executed and imprisoned as "enemies of the people" by their colleagues). The rank-and-file people in these organizations are also very incompetent, they have no incentive to *be* competent (no actual competition, and being above the herd attracts the unwelcome resentment from the officemates).

That's why I'm not much worried about the nightmare scenario of DHS/NSA/FBI turning into a totalitarian omnipresent and omnipotent gang. Nobody can turn these ossified bureaucratic boondoggles into anything dangerous on a large scale; not before US falls apart for economic reasons.

They still can make life very miserable for some people unlucky enough to attract attention of their bosses, but the occasional bouts of institutional sadism only serve to hasten their downfall by creating more and more enemies out of people who wouldn't otherwise care.

bruce mangee • August 7, 2013 4:07 AM

In the light of TEMPORA and PRISM Tor is compromized in the USA and Europe.
Timestamps become very revealing if all comunication of Tor nodes can be recorded by the NSA.
So use more Tor, so that the SNR favors our anonymity ... :)

Clive Robinson • August 7, 2013 4:21 AM

The title of this blog entry "Has TOR been compramised" is in the past tense which is unfortunate.

Due to a number of issues TOR has some very definate short comings which give rise to a viewpoint that TOR has is and probably always will be compromised to some extent.

As others have pointed out above there are other networks that have addressed some of TORs failings, but they to have other failings which are due to the actuall real physical layer structure of the Internet. I've mentioned this latter point a number of times befor on this blog.

One point most secure darknet designers miss or chose to ignore is the issue of having a secure side channel which enables the establishment of trust in a roubust way. Ignoring it or pretending that PK will do instead does not solve the problem it just moves it around a little. It is an issue we are a long long way from solving and why surprise suprise One Time Pads delivered by secure couriers are still used by certain organisations.

Another asspect is "end point security" I have mentioned many times the problem with "end run" vulnerability and we saw this with the CarrierIQ mess not so long ago. To have even a semblance of security in your communications you need to lock the end points down. Some commercial VPN suppliers are well aware of this which is why disable or entirely replace the network stack in a PC, or they use a physical secure network bridge that alows the end point to be issolated and security to be ensured.

But technical issues aside the "elephant in the room" issue with TOR and for that matter any of the other networks is the number of users and usability.

You could create the darkest of darknets molded around the Internet limitations, offering high levels of security, but for the majority of mortals it would be unusable.

Each step you take in the direction of "usability for the masses" will almost certainly require some asspect of security to be effected in a negative way. The greater the negative impact the easier it will become to find an attack vector it is just a matter of resources. And the greater the number of users the more economical those resources become in terms of $expendeture/user.

This particular attack can be viewed as a very low hanging fruit attack against TOR and I'm reasonably certain there are more sophisticated attacks already in place at several levels. Thus to ask in the past tense about TOR usage being compromised is in effect looking backwards on the issue, we should be asking how is it compramised now and how do we limit in the future.

Thus as I've indicated before TOR is not

Adam • August 7, 2013 4:23 AM

What surprises me is that anyone ever thought Tor was secure. It might anonymize who you are as far as the server is concerned but at the end of the day, a node still has to connect to the server and that node may well be run by a government agency. A hidden service still has to talk to a server and it's very easy for someone to set up a legit looking site and monitor visitors. They could modify the content of the site, install an "evercookie", add headers, or otherwise mess with the content in a way which disrupts the service or traces the requester.

It looks like in this instance someone has hacked existing hidden services rather than setting up their own but who says that hasn't happened too?

It must prove a highly tempting target too. There must be a far higher concentration of illegal activity happening through Tor than normal internet use, and traffic of interest to intelligence agencies (e.g. political activists, rumours etc.).

Isaiah • August 7, 2013 5:53 AM

Im new to tor so help me out here. Does the exploit or whatever, include the mobile tor bot/web.

wiredog • August 7, 2013 5:54 AM

I am shocked, shocked I tell you, that the US government was able to compromise part of a system that was designed and originally deployed by the US government!

Willey Gates • August 7, 2013 6:13 AM

I strongly disagree with this idea that "Tor itself hasn't been compromised." While that is true in a technical sense it is false in a holistic sense. Many unsophisticated people put their trust in the TBB-Tor Browser Bundle. Tor encouraged this behavior, indeed they went so far as to turn Javascript on by default in TBB order to make browsing the web easier for these unsophisticated folks

Completely agree and more!! I want to scream I told you so at soo many people who used the TBB and thought it great to customize it and make it as close as possible to the browser they use all the time... These are the fools who you dumbed down TOR software for!! Leaving JS enabled and expecting M$ users to disable it every time. I can't get M$ users to take the most basic precautions and recommendations they sometimes pay me for!!

Is it any surprise that they went after the TBB as it is almost 100% a windows users tool. I can't imagine a *nix user choosing it over a nice Debian based tool like Tails(which has JS enabled by default too!!!!!!!
Dropped the ball by trying to dumb things down so Windows users could continue to not learn anything.... WEAK!

John Doe • August 7, 2013 6:13 AM

On what grounds is the FBI being suspected of compromising tor? Even the headline is somewhat shoddy journalism.... and then we get to the fact that the vulnerability wasn't even with tor.

The only mention of the FBI was the the journalist giving an anecdotal nod to the fact that this compromise occurred around the time another individual was arrested. In that case the FBI declined to comment on the ongoing criminal investigation.

Could this not be more vigilante justice by Anonymous? Even the article states that the hosting provider was last targeted by Anonymous in 2011... Maybe its just by cyber gang on cyber gang violence, freedom hosting also hosts hacker forums, could even be someone looking to extort and blackmail the kiddie porn viewers....

FBI doesn't seem the most likely source of a malware infection like this....

Willey Gates • August 7, 2013 6:19 AM

"Does the exploit or whatever, include the mobile tor bot/web. "

in my eye's accessing TOR from a mobile device, god help you an iDevice, using orbot/orweb, or ."to" sites or whatever that nonsense is called is about the silliest thing to even consider if you hope for any kind of security. If TOR is secure it is most definitely much LESS secure if using a mobile device(you experts out there may know how to keep safe using a mobile device, but I'm talking about the other 99%) Be safe everyone

willey gates • August 7, 2013 6:31 AM

Well, those naysayers were proven right. The gun might have been Firefox and the FBI might have been the triggerman but it was Tor and Tor alone that gathered all the fish in the barrel.

I am def one of those who have been attacked for claiming that the dumbing down of TOR is a bad idea and potential bad for any TOR users even those of "you" who take every proper measure that we "believe" will help. Something so serious with such huge consequences as even non-violent drug convictions in the US can amount to a death sentence for many is not something to "Make more user(idiot) friendly"

TO ALL THOSE WHO BASHED ME WHILE TRYING TO HELP, I TOLD YOU SO!!

New Usher • August 7, 2013 6:32 AM

As long as you are not committing any serious crime, any relatively secure system (TOR, VPN, PGP) will be enough to keep the FBI or NSA from seeing what you are doing. They could break your security, if they put in enough time, money, and effort. But they won't devote the resources, unless you give them a reason to do so.

Winter • August 7, 2013 8:10 AM

Yes, TOR is not perfect. TBB is not the best TOR could deliver. But perfect security costs an infinite amount of effort and/or money. Real security balances effort/cost and protection.

TOR and TBB are real security. If you can point out a better balance, say, better security for less effort, or an increment in cost for an increment in security, please inform us.

And, to all those saying TBB is too insecure, what should dissidents in, e.g., the ME or Russia, use instead? Or should they simply stop speaking?

unknown.soldier • August 7, 2013 10:23 AM


John Doe • August 7, 2013 6:13 AM
On what grounds is the FBI being suspected of compromising tor? Even the headline is somewhat shoddy journalism.... and then we get to the fact that the vulnerability wasn't even with tor.
The only mention of the FBI was the the journalist giving an anecdotal nod to the fact that this compromise occurred around the time another individual was arrested.

I am not aware of evidence it is FBI, but there is evidence it is US Government, and local dealings do go in the domain of the FBI whether it is the CIA, NSA, or whomever else.

from ARS:
"Initial investigations traced the address to defense contractor SAIC, which provides a wide range of information technology and C4ISR (Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance) support to the Department of Defense. The geolocation of the IP address corresponds to an SAIC facility in Arlington, Virginia.

Further analysis using a DNS record tool from Robtex found that the address was actually part of several blocks of IP addresses allocated by SAIC to the NSA. This immediately spooked the researchers."


Not conclusive evidence, but the FBI would be a Usual Suspect.

Does this matter?

They do do these sorts of things, there is plenty of evidence on that.

Thecaseforpeace • August 7, 2013 11:07 AM

Any security measure will have vulnerabilities. Tor is no exception. If security is very important to you, use multiple security countermeasures (remember defense-in-depth):

Public WiFi
VPN
Tor
Browser hardening

I highly doubt that the NSA has broken Tor completely. Anyone familiar with the architecture of Tor knows it is a 3 tier system. Entry node > Relay > Exit node

The Entry node is only aware of the IP address of the TOR client connecting to it. All traffic is encrypted.

The midpoint relay is only aware of encrypted traffic coming from the entry node.

The exit node is aware of traffic coming from the midpoint relay and the plaintext web traffic going to the destination website, but is not aware of who the Tor client is.

The NSA to break basic TOR would have to pwn a large population of relays in order to put the picture together - maybe somebody can do the math of how many they would need to own?

The NSA can certainly detect that a computer is running Tor, because it's a unique signature of HTTPS traffic. This has been something the torproject has been working on for some time to slip by Chinese and other censorship regimes. They block it for a while, then Torproject figures out a new way to obfuscate. But there's a lot of people running Tor for a variety of reasons, including humanitarian causes, IT security people, and .gov people. Running Tor alone is not damning in any way. Then again, you can mitigate the knowledge you are running the service by using a VPN or public Internet connection.

G van Grijnen • August 7, 2013 4:32 PM

@Brian Lee,

The whole idea of blending in with the crowd is that nobody is monitoring your traffic.

To be more specific, you could hide your OTP message in the huge comments section of the most visited websites in the world, like Yahoo, CNN and others.

Traffic monitoring would be pretty difficult.

Basically this would protect sender, message and receiver.

Dirk Praet • August 7, 2013 6:41 PM

@ Clive

... will almost certainly require some asspect of security to be effected in a negative way.

Definitely one of your best typos to date, knowing that pect in the medical dictionary stands for perivascular epithelioid cell tumor. Reminds me of a Monty Python-like moment in Rome when a French collegue of mine in his best Italian asked for a "shampoo pelliculo" in a local grocery store. What he meant was a dandruff shampoo, in French "shampooing anti-pelliculaire". What the shopkeeper and the rest of the company had understood was "a shampoo for the ass" (culo in Italian). The poor guy had no idea why we nearly pissed ourselves laughing.

I fully concur with your Tor analysis. What I meant to point out was that Tor and Tor nodes are no more or less compromised by this particular TBB exploit.

Wael • August 7, 2013 6:54 PM

@ Dirk Praet

Definitely one of your best typos to date...

Clive Robinson is consistent! Search for "asspect" and tell me how many times he spelled it that way ;)

I also concur with the Tor piece...

CallMeLateForSupper • August 8, 2013 1:52 PM

@Geweihir
"...the exploit just contacted an external server directly while the Tor session was still running."

This is my understanding too. The server was contacted via an HTTP session.

Interestingly, Firefox v23 was released just yesterday, and one new thing in it is that an HTTP session cannot be opened from within an HTTPS session.

A side not: Another new thing in FF v23 is that the checkbox ON/OFF control for Javascript is gone... GONE. Javascript defaults to ON, and changing the setting is now very, very clunky. Mozilla's explanation - protecting the unknowledgable user from unwittingly breaking his web experience - just plain sucks.

I turn Javascript ON at least once per day - it's required by my email - and turn it off immediately when I'm done. Since controlling Javascript is a kludge in FF v23, I won't be upgrading anytime soo,.

Nick P • August 9, 2013 10:42 AM

Navy was one of Tor's originators. Navy's excellent CHACS lab still works on anonymity. Here's a few nice pieces from them.

Strong, Scalable Anonymity in DISSENT (2012)
http://www.nrl.navy.mil/itd/chacs/node/24

Presents an alternative anonymity scheme with excellent scaling properties. Simulations show latencies are as low as "3 seconds for network sizes of 500." That's nice.

Security Analysis of Accountable Anonymous Group Communication in Dissent (2013)
http://www.nrl.navy.mil/itd/chacs/node/195

They discuss problems with a few types of networks. Then, they improve on Dissent and analyse it for its properties.

LIRA: Lightweight Incentivized Routing for Anonymity (2013)
http://www.nrl.navy.mil/itd/chacs/node/23

Improve Tor performance and (to lesser extent) anonymity via a lottery scheme to encourage users to contribute bandwidth.

Questor • August 9, 2013 4:22 PM

This brings to mind something my supervisor told me yesterday. She worked previously for Tyco where, according to her, they did a fair amount of work for Department of Defense.

She said for example that one of the DoD contractors did a demonstration with another persons computer (the target had agreed to this) where they sent a "bullet" (I guess a network packet of some type) to the persons computer. This had two effects: 1) it caused the computer to crash, and 2) it wiped out the HD.

According to her this contractor had informed her that the government is "able to break into any computer and see what the person is currently viewing on the screen". She said that the only thing that limits the use of this is the sheer amount of computers.

Whilst I cannot deny that something like these is possible, she also said something else that I wanted to bring up here in the hopes that I am shown that it is not possible: namely that the government can decrypt all encrypted algorithms because they own their implementation.

The problem with that statement is that I thought the algorithms use methods that only work one way, and not the other (i.e. once they encrypt something, it cannot be decrypted).

So maybe she has misunderstood something or has been misinformed(?). Or maybe what she says is possible if the encryption systems somehow provide information that makes it possible to decrypt the data streams?

SF Kinney • August 9, 2013 11:10 PM

@questor, I do believe you have been pretty substantially misinformed. With regard to a "bullet" network packet that can crash a system and/or wipe the hard drive, there are a couple of large problems with that.

First, that packet might have to make it past a hardware firewall in the form of an ordinary router, and a software firewall that simply drops any packet that's not a reply to a current outbound connection request. These considerations put a quick stop to the "any computer" claim; at minimum, the target system has to be profiled in detail, including any hardware firewall that's in the way, and somehow "cracked" at the device driver level via exploits that resemble nothing anyone has discovered in the private sector. This is most unlikely, and approximately "impossible" if we are talking about hitting any system, any time.

The part about wiping out the hard drive - that takes a lot more than crashing a system, among other things it takes substantial time, and if the user notices the process in progress he or she can stop it at the power switch. One exception might be to wipe the locally stored cipher key for an encrypted container, which would "wipe out" the contents of the drive unless the user had a backup of the key available; but again, this rules out the "any system, any time" assertion - and the problem of getting the exploit code into the target system remains.

Viewing the current desktop display of any machine, any time on demand? Again, not. There are numerous tools and techniques that make it possible, but none that can do it to "any computer at any time," and some well managed machines may resist any and all such attacks for a long time.

Breaking any cryptographic protocol at any time? Again, not. It is approximately impossible that all of the peer reviewed open source crypto tools are compromised, and just not possible that they have all remained so for a long time. However, this may be completely true of crypto protocols provided as closed source "binary blobs" by vendors, i.e. Microsoft, who have little to lose and the world to gain by selling out their customers at home and abroad.

noname • August 10, 2013 2:40 PM

@secret police

There is nothing insane about activating javascript.

If you use TOR to browse normal web, you "blend in" better with javascript on (because everyone and their dog has it "on")

Now, as to javascript being a security liability, it's not a remarkable one.

Yes, it is yet one more attack surface, and yes, this particular attack leveraged an error in javascript implementation, but please tell, how is that fundamentally different from an error in, say, .png rendering code?

And what makes you think that there isn't a (yet unknown) remote exploit in your platform of choice's png rendering code ?

questor • September 5, 2013 8:53 PM

SF Kinney • August 9, 2013 11:10 PM


@questor, I do believe you have been pretty substantially misinformed. With regard to a "bullet" network packet that can crash a system and/or wipe the hard drive, there are a couple of large problems with that.
[...]
Viewing the current desktop display of any machine, any time on demand? Again, not...
[...]
Breaking any cryptographic protocol at any time? Again, not...

Actually, SF Kinney, reading Schneiers articles about the Snowden documents makes me think that the information from my manager was not that misleading after all

none • October 28, 2013 9:39 AM

stop recommending JonDo ! They put a backdoor and after it came out they said "what would you do in our position ?"

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