Entries Tagged "vulnerabilities"

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WannaCry and Vulnerabilities

There is plenty of blame to go around for the WannaCry ransomware that spread throughout the Internet earlier this month, disrupting work at hospitals, factories, businesses, and universities. First, there are the writers of the malicious software, which blocks victims’ access to their computers until they pay a fee. Then there are the users who didn’t install the Windows security patch that would have prevented an attack. A small portion of the blame falls on Microsoft, which wrote the insecure code in the first place. One could certainly condemn the Shadow Brokers, a group of hackers with links to Russia who stole and published the National Security Agency attack tools that included the exploit code used in the ransomware. But before all of this, there was the NSA, which found the vulnerability years ago and decided to exploit it rather than disclose it.

All software contains bugs or errors in the code. Some of these bugs have security implications, granting an attacker unauthorized access to or control of a computer. These vulnerabilities are rampant in the software we all use. A piece of software as large and complex as Microsoft Windows will contain hundreds of them, maybe more. These vulnerabilities have obvious criminal uses that can be neutralized if patched. Modern software is patched all the time—either on a fixed schedule, such as once a month with Microsoft, or whenever required, as with the Chrome browser.

When the US government discovers a vulnerability in a piece of software, however, it decides between two competing equities. It can keep it secret and use it offensively, to gather foreign intelligence, help execute search warrants, or deliver malware. Or it can alert the software vendor and see that the vulnerability is patched, protecting the country—and, for that matter, the world—from similar attacks by foreign governments and cybercriminals. It’s an either-or choice. As former US Assistant Attorney General Jack Goldsmith has said, “Every offensive weapon is a (potential) chink in our defense—and vice versa.”

This is all well-trod ground, and in 2010 the US government put in place an interagency Vulnerabilities Equities Process (VEP) to help balance the trade-off. The details are largely secret, but a 2014 blog post by then President Barack Obama’s cybersecurity coordinator, Michael Daniel, laid out the criteria that the government uses to decide when to keep a software flaw undisclosed. The post’s contents were unsurprising, listing questions such as “How much is the vulnerable system used in the core Internet infrastructure, in other critical infrastructure systems, in the US economy, and/or in national security systems?” and “Does the vulnerability, if left unpatched, impose significant risk?” They were balanced by questions like “How badly do we need the intelligence we think we can get from exploiting the vulnerability?” Elsewhere, Daniel has noted that the US government discloses to vendors the “overwhelming majority” of the vulnerabilities that it discovers—91 percent, according to NSA Director Michael S. Rogers.

The particular vulnerability in WannaCry is code-named EternalBlue, and it was discovered by the US government—most likely the NSA—sometime before 2014. The Washington Post reported both how useful the bug was for attack and how much the NSA worried about it being used by others. It was a reasonable concern: many of our national security and critical infrastructure systems contain the vulnerable software, which imposed significant risk if left unpatched. And yet it was left unpatched.

There’s a lot we don’t know about the VEP. The Washington Post says that the NSA used EternalBlue “for more than five years,” which implies that it was discovered after the 2010 process was put in place. It’s not clear if all vulnerabilities are given such consideration, or if bugs are periodically reviewed to determine if they should be disclosed. That said, any VEP that allows something as dangerous as EternalBlue—or the Cisco vulnerabilities that the Shadow Brokers leaked last August to remain unpatched for years isn’t serving national security very well. As a former NSA employee said, the quality of intelligence that could be gathered was “unreal.” But so was the potential damage. The NSA must avoid hoarding vulnerabilities.

Perhaps the NSA thought that no one else would discover EternalBlue. That’s another one of Daniel’s criteria: “How likely is it that someone else will discover the vulnerability?” This is often referred to as NOBUS, short for “nobody but us.” Can the NSA discover vulnerabilities that no one else will? Or are vulnerabilities discovered by one intelligence agency likely to be discovered by another, or by cybercriminals?

In the past few months, the tech community has acquired some data about this question. In one study, two colleagues from Harvard and I examined over 4,300 disclosed vulnerabilities in common software and concluded that 15 to 20 percent of them are rediscovered within a year. Separately, researchers at the Rand Corporation looked at a different and much smaller data set and concluded that fewer than six percent of vulnerabilities are rediscovered within a year. The questions the two papers ask are slightly different and the results are not directly comparable (we’ll both be discussing these results in more detail at the Black Hat Conference in July), but clearly, more research is needed.

People inside the NSA are quick to discount these studies, saying that the data don’t reflect their reality. They claim that there are entire classes of vulnerabilities the NSA uses that are not known in the research world, making rediscovery less likely. This may be true, but the evidence we have from the Shadow Brokers is that the vulnerabilities that the NSA keeps secret aren’t consistently different from those that researchers discover. And given the alarming ease with which both the NSA and CIA are having their attack tools stolen, rediscovery isn’t limited to independent security research.

But even if it is difficult to make definitive statements about vulnerability rediscovery, it is clear that vulnerabilities are plentiful. Any vulnerabilities that are discovered and used for offense should only remain secret for as short a time as possible. I have proposed six months, with the right to appeal for another six months in exceptional circumstances. The United States should satisfy its offensive requirements through a steady stream of newly discovered vulnerabilities that, when fixed, also improve the country’s defense.

The VEP needs to be reformed and strengthened as well. A report from last year by Ari Schwartz and Rob Knake, who both previously worked on cybersecurity policy at the White House National Security Council, makes some good suggestions on how to further formalize the process, increase its transparency and oversight, and ensure periodic review of the vulnerabilities that are kept secret and used for offense. This is the least we can do. A bill recently introduced in both the Senate and the House calls for this and more.

In the case of EternalBlue, the VEP did have some positive effects. When the NSA realized that the Shadow Brokers had stolen the tool, it alerted Microsoft, which released a patch in March. This prevented a true disaster when the Shadow Brokers exposed the vulnerability on the Internet. It was only unpatched systems that were susceptible to WannaCry a month later, including versions of Windows so old that Microsoft normally didn’t support them. Although the NSA must take its share of the responsibility, no matter how good the VEP is, or how many vulnerabilities the NSA reports and the vendors fix, security won’t improve unless users download and install patches, and organizations take responsibility for keeping their software and systems up to date. That is one of the important lessons to be learned from WannaCry.

This essay originally appeared in Foreign Affairs.

Posted on June 2, 2017 at 6:06 AM • View Comments

Who Are the Shadow Brokers?

In 2013, a mysterious group of hackers that calls itself the Shadow Brokers stole a few disks full of NSA secrets. Since last summer, they’ve been dumping these secrets on the Internet. They have publicly embarrassed the NSA and damaged its intelligence-gathering capabilities, while at the same time have put sophisticated cyberweapons in the hands of anyone who wants them. They have exposed major vulnerabilities in Cisco routers, Microsoft Windows, and Linux mail servers, forcing those companies and their customers to scramble. And they gave the authors of the WannaCry ransomware the exploit they needed to infect hundreds of thousands of computer worldwide this month.

After the WannaCry outbreak, the Shadow Brokers threatened to release more NSA secrets every month, giving cybercriminals and other governments worldwide even more exploits and hacking tools.

Who are these guys? And how did they steal this information? The short answer is: we don’t know. But we can make some educated guesses based on the material they’ve published.

The Shadow Brokers suddenly appeared last August, when they published a series of hacking tools and computer exploits­—vulnerabilities in common software—­from the NSA. The material was from autumn 2013, and seems to have been collected from an external NSA staging server, a machine that is owned, leased, or otherwise controlled by the US, but with no connection to the agency. NSA hackers find obscure corners of the Internet to hide the tools they need as they go about their work, and it seems the Shadow Brokers successfully hacked one of those caches.

In total, the group has published four sets of NSA material: a set of exploits and hacking tools against routers, the devices that direct data throughout computer networks; a similar collection against mail servers; another collection against Microsoft Windows; and a working directory of an NSA analyst breaking into the SWIFT banking network. Looking at the time stamps on the files and other material, they all come from around 2013. The Windows attack tools, published last month, might be a year or so older, based on which versions of Windows the tools support.

The releases are so different that they’re almost certainly from multiple sources at the NSA. The SWIFT files seem to come from an internal NSA computer, albeit one connected to the Internet. The Microsoft files seem different, too; they don’t have the same identifying information that the router and mail server files do. The Shadow Brokers have released all the material unredacted, without the care journalists took with the Snowden documents or even the care WikiLeaks has taken with the CIA secrets it’s publishing. They also posted anonymous messages in bad English but with American cultural references.

Given all of this, I don’t think the agent responsible is a whistleblower. While possible, it seems like a whistleblower wouldn’t sit on attack tools for three years before publishing. They would act more like Edward Snowden or Chelsea Manning, collecting for a time and then publishing immediately­—and publishing documents that discuss what the US is doing to whom. That’s not what we’re seeing here; it’s simply a bunch of exploit code, which doesn’t have the political or ethical implications that a whistleblower would want to highlight. The SWIFT documents are records of an NSA operation, and the other posted files demonstrate that the NSA is hoarding vulnerabilities for attack rather than helping fix them and improve all of our security.

I also don’t think that it’s random hackers who stumbled on these tools and are just trying to harm the NSA or the US. Again, the three-year wait makes no sense. These documents and tools are cyber-Kryptonite; anyone who is secretly hoarding them is in danger from half the intelligence agencies in the world. Additionally, the publication schedule doesn’t make sense for the leakers to be cybercriminals. Criminals would use the hacking tools for themselves, incorporating the exploits into worms and viruses, and generally profiting from the theft.

That leaves a nation state. Whoever got this information years before and is leaking it now has to be both capable of hacking the NSA and willing to publish it all. Countries like Israel and France are capable, but would never publish, because they wouldn’t want to incur the wrath of the US. Countries like North Korea or Iran probably aren’t capable. (Additionally, North Korea is suspected of being behind WannaCry, which was written after the Shadow Brokers released that vulnerability to the public.) As I’ve written previously, the obvious list of countries who fit my two criteria is small: Russia, China, and­—I’m out of ideas. And China is currently trying to make nice with the US.

It was generally believed last August, when the first documents were released and before it became politically controversial to say so, that the Russians were behind the leak, and that it was a warning message to President Barack Obama not to retaliate for the Democratic National Committee hacks. Edward Snowden guessed Russia, too. But the problem with the Russia theory is, why? These leaked tools are much more valuable if kept secret. Russia could use the knowledge to detect NSA hacking in its own country and to attack other countries. By publishing the tools, the Shadow Brokers are signaling that they don’t care if the US knows the tools were stolen.

Sure, there’s a chance the attackers knew that the US knew that the attackers knew—­and round and round we go. But the “we don’t give a damn” nature of the releases points to an attacker who isn’t thinking strategically: a lone hacker or hacking group, which clashes with the nation-state theory.

This is all speculation on my part, based on discussion with others who don’t have access to the classified forensic and intelligence analysis. Inside the NSA, they have a lot more information. Many of the files published include operational notes and identifying information. NSA researchers know exactly which servers were compromised, and through that know what other information the attackers would have access to. As with the Snowden documents, though, they only know what the attackers could have taken and not what they did take. But they did alert Microsoft about the Windows vulnerability the Shadow Brokers released months in advance. Did they have eavesdropping capability inside whoever stole the files, as they claimed to when the Russians attacked the State Department? We have no idea.

So, how did the Shadow Brokers do it? Did someone inside the NSA accidentally mount the wrong server on some external network? That’s possible, but seems very unlikely for the organization to make that kind of rookie mistake. Did someone hack the NSA itself? Could there be a mole inside the NSA?

If it is a mole, my guess is that the person was arrested before the Shadow Brokers released anything. No country would burn a mole working for it by publishing what that person delivered while he or she was still in danger. Intelligence agencies know that if they betray a source this severely, they’ll never get another one.

That points to two possibilities. The first is that the files came from Hal Martin. He’s the NSA contractor who was arrested in August for hoarding agency secrets in his house for two years. He can’t be the publisher, because the Shadow Brokers are in business even though he is in prison. But maybe the leaker got the documents from his stash, either because Martin gave the documents to them or because he himself was hacked. The dates line up, so it’s theoretically possible. There’s nothing in the public indictment against Martin that speaks to his selling secrets to a foreign power, but that’s just the sort of thing that would be left out. It’s not needed for a conviction.

If the source of the documents is Hal Martin, then we can speculate that a random hacker did in fact stumble on it—­no need for nation-state cyberattack skills.

The other option is a mysterious second NSA leaker of cyberattack tools. Could this be the person who stole the NSA documents and passed them on to someone else? The only time I have ever heard about this was from a Washington Post story about Martin:

There was a second, previously undisclosed breach of cybertools, discovered in the summer of 2015, which was also carried out by a TAO employee [a worker in the Office of Tailored Access Operations], one official said. That individual also has been arrested, but his case has not been made public. The individual is not thought to have shared the material with another country, the official said.

Of course, “not thought to have” is not the same as not having done so.

It is interesting that there have been no public arrests of anyone in connection with these hacks. If the NSA knows where the files came from, it knows who had access to them—­and it’s long since questioned everyone involved and should know if someone deliberately or accidentally lost control of them. I know that many people, both inside the government and out, think there is some sort of domestic involvement; things may be more complicated than I realize.

It’s also not over. Last week, the Shadow Brokers were back, with a rambling and taunting message announcing a “Data Dump of the Month” service. They’re offering to sell unreleased NSA attack tools­—something they also tried last August­—with the threat to publish them if no one pays. The group has made good on their previous boasts: In the coming months, we might see new exploits against web browsers, networking equipment, smartphones, and operating systems—Windows in particular. Even scarier, they’re threatening to release raw NSA intercepts: data from the SWIFT network and banks, and “compromised data from Russian, Chinese, Iranian, or North Korean nukes and missile programs.”

Whoever the Shadow Brokers are, however they stole these disks full of NSA secrets, and for whatever reason they’re releasing them, it’s going to be a long summer inside of Fort Meade­—as it will be for the rest of us.

This essay previously appeared in the Atlantic, and is an update of this essay from Lawfare.

Posted on May 30, 2017 at 6:08 AM • View Comments

Attack vs. Defense in Nation-State Cyber Operations

I regularly say that, on the Internet, attack is easier than defense. There are a bunch of reasons for this, but primarily it’s 1) the complexity of modern networked computer systems and 2) the attacker’s ability to choose the time and method of the attack versus the defender’s necessity to secure against every type of attack. This is true, but how this translates to military cyber-operations is less straightforward. Contrary to popular belief, government cyberattacks are not bolts out of the blue, and the attack/defense balance is more…well…balanced.

Rebecca Slayton has a good article in International Security that tries to make sense of this: “What is the Cyber Offense-Defense Balance? Conceptions, Causes, and Assessment.” In it, she points out that launching a cyberattack is more than finding and exploiting a vulnerability, and it is those other things that help balance the offensive advantage.

Posted on April 13, 2017 at 5:45 AM • View Comments

Fourth WikiLeaks CIA Attack Tool Dump

WikiLeaks is obviously playing their Top Secret CIA data cache for as much press as they can, leaking the documents a little at a time. On Friday they published their fourth set of documents from what they call “Vault 7”:

27 documents from the CIA’s Grasshopper framework, a platform used to build customized malware payloads for Microsoft Windows operating systems.

We have absolutely no idea who leaked this one. When they first started appearing, I suspected that it was not an insider because there wasn’t anything illegal in the documents. There still isn’t, but let me explain further. The CIA documents are all hacking tools. There’s nothing about programs or targets. Think about the Snowden leaks: it was the information about programs that targeted Americans, programs that swept up much of the world’s information, programs that demonstrated particularly powerful NSA capabilities. There’s nothing like that in the CIA leaks. They’re just hacking tools. All they demonstrate is that the CIA hoards vulnerabilities contrary to the government’s stated position, but we already knew that.

This was my guess from March:

If I had to guess right now, I’d say the documents came from an outsider and not an insider. My reasoning: One, there is absolutely nothing illegal in the contents of any of this stuff. It’s exactly what you’d expect the CIA to be doing in cyberspace. That makes the whistleblower motive less likely. And two, the documents are a few years old, making this more like the Shadow Brokers than Edward Snowden. An internal leaker would leak quickly. A foreign intelligence agency—like the Russians—would use the documents while they were fresh and valuable, and only expose them when the embarrassment value was greater.

But, as I said last month, no one has any idea: we’re all guessing. (Well, to be fair, I hope the CIA knows exactly who did this. Or, at least, exactly where the documents were stolen from.) And I hope the inability of either the NSA or CIA to keep its own attack tools secret will cause them to rethink their decision to hoard vulnerabilities in common Internet systems instead of fixing them.

News articles.

EDITED TO ADD (4/12): An analysis.

Posted on April 10, 2017 at 2:16 PM • View Comments

Many Android Phones Vulnerable to Attacks Over Malicious Wi-Fi Networks

There’s a blog post from Google’s Project Zero detailing an attack against Android phones over Wi-Fi. From Ars Technica:

The vulnerability resides in a widely used Wi-Fi chipset manufactured by Broadcom and used in both iOS and Android devices. Apple patched the vulnerability with Monday’s release of iOS 10.3.1. “An attacker within range may be able to execute arbitrary code on the Wi-Fi chip,” Apple’s accompanying advisory warned. In a highly detailed blog post published Tuesday, the Google Project Zero researcher who discovered the flaw said it allowed the execution of malicious code on a fully updated 6P “by Wi-Fi proximity alone, requiring no user interaction.”

Google is in the process of releasing an update in its April security bulletin. The fix is available only to a select number of device models, and even then it can take two weeks or more to be available as an over-the-air update to those who are eligible. Company representatives didn’t respond to an e-mail seeking comment for this post.

The proof-of-concept exploit developed by Project Zero researcher Gal Beniamini uses Wi-Fi frames that contain irregular values. The values, in turn, cause the firmware running on Broadcom’s wireless system-on-chip to overflow its stack. By using the frames to target timers responsible for carrying out regularly occurring events such as performing scans for adjacent networks, Beniamini managed to overwrite specific regions of device memory with arbitrary shellcode. Beniamini’s code does nothing more than write a benign value to a specific memory address. Attackers could obviously exploit the same series of flaws to surreptitiously execute malicious code on vulnerable devices within range of a rogue access point.

Slashdot thread.

Posted on April 6, 2017 at 7:52 AM • View Comments

WikiLeaks Not Disclosing CIA-Hoarded Vulnerabilities to Companies

WikiLeaks has started publishing a large collection of classified CIA documents, including information on several—possibly many—unpublished (i.e., zero-day) vulnerabilities in computing equipment used by Americans. Despite assurances that the US government prioritizes defense over offense, it seems that the CIA was hoarding vulnerabilities. (It’s not just the CIA; last year we learned that the NSA is, too.)

Publishing those vulnerabilities into the public means that they’ll get fixed, but it also means that they’ll be used by criminals and other governments in the time period between when they’re published and when they’re patched. WikiLeaks has said that it’s going to do the right thing and privately disclose those vulnerabilities to the companies first.

This process seems to be hitting some snags:

This week, Assange sent an email to Apple, Google, Microsoft and all the companies mentioned in the documents. But instead of reporting the bugs or exploits found in the leaked CIA documents it has in its possession, WikiLeaks made demands, according to multiple sources familiar with the matter who spoke on condition of anonymity.

WikiLeaks included a document in the email, requesting the companies to sign off on a series of conditions before being able to receive the actual technical details to deploy patches, according to sources. It’s unclear what the conditions are, but a source mentioned a 90-day disclosure deadline, which would compel companies to commit to issuing a patch within three months.

I’m okay with a 90-day window; that seems reasonable. But I have no idea what the other conditions are, and how onerous they are.

Honestly, at this point the CIA should do the right thing and disclose all the vulnerabilities to the companies. They’re burned as CIA attack tools. I have every confidence that Russia, China, and several other countries can hack WikiLeaks and get their hands on a copy. By now, their primary value is for defense. The CIA should bypass WikiLeaks and get the vulnerabilities fixed as soon as possible.

Posted on March 21, 2017 at 6:05 AM • View Comments

Google Discloses Details of an Unpatched Microsoft Vulnerability

Google’s Project Zero is serious about releasing the details of security vulnerabilities 90 days after they alert the vendors, even if they’re unpatched. It just exposed a nasty vulnerability in Microsoft’s browsers.

This is the second unpatched Microsoft vulnerability it exposed last week.

I’m a big fan of responsible disclosure. The threat to publish vulnerabilities is what puts pressure on vendors to patch their systems. But I wonder what competitive pressure is on the Google team to find embarrassing vulnerabilities in competitors’ products.

Posted on March 9, 2017 at 6:28 AM • View Comments

WhatsApp Security Vulnerability

Back in March, Rolf Weber wrote about a potential vulnerability in the WhatsApp protocol that would allow Facebook to defeat perfect forward secrecy by forcibly change users’ keys, allowing it—or more likely, the government—to eavesdrop on encrypted messages.

It seems that this vulnerability is real:

WhatsApp has the ability to force the generation of new encryption keys for offline users, unbeknown to the sender and recipient of the messages, and to make the sender re-encrypt messages with new keys and send them again for any messages that have not been marked as delivered.

The recipient is not made aware of this change in encryption, while the sender is only notified if they have opted-in to encryption warnings in settings, and only after the messages have been re-sent. This re-encryption and rebroadcasting effectively allows WhatsApp to intercept and read users’ messages.

The security loophole was discovered by Tobias Boelter, a cryptography and security researcher at the University of California, Berkeley. He told the Guardian: “If WhatsApp is asked by a government agency to disclose its messaging records, it can effectively grant access due to the change in keys.”

The vulnerability is not inherent to the Signal protocol. Open Whisper Systems’ messaging app, Signal, the app used and recommended by whistleblower Edward Snowden, does not suffer from the same vulnerability. If a recipient changes the security key while offline, for instance, a sent message will fail to be delivered and the sender will be notified of the change in security keys without automatically resending the message.

WhatsApp’s implementation automatically resends an undelivered message with a new key without warning the user in advance or giving them the ability to prevent it.

Note that it’s an attack against current and future messages, and not something that would allow the government to reach into the past. In that way, it is no more troubling than the government hacking your mobile phone and reading your WhatsApp conversations that way.

An unnamed “WhatsApp spokesperson” said that they implemented the encryption this way for usability:

In WhatsApp’s implementation of the Signal protocol, we have a “Show Security Notifications” setting (option under Settings > Account > Security) that notifies you when a contact’s security code has changed. We know the most common reasons this happens are because someone has switched phones or reinstalled WhatsApp. This is because in many parts of the world, people frequently change devices and Sim cards. In these situations, we want to make sure people’s messages are delivered, not lost in transit.

He’s technically correct. This is not a backdoor. This really isn’t even a flaw. It’s a design decision that put usability ahead of security in this particular instance. Moxie Marlinspike, creator of Signal and the code base underlying WhatsApp’s encryption, said as much:

Under normal circumstances, when communicating with a contact who has recently changed devices or reinstalled WhatsApp, it might be possible to send a message before the sending client discovers that the receiving client has new keys. The recipient’s device immediately responds, and asks the sender to reencrypt the message with the recipient’s new identity key pair. The sender displays the “safety number has changed” notification, reencrypts the message, and delivers it.

The WhatsApp clients have been carefully designed so that they will not re-encrypt messages that have already been delivered. Once the sending client displays a “double check mark,” it can no longer be asked to re-send that message. This prevents anyone who compromises the server from being able to selectively target previously delivered messages for re-encryption.

The fact that WhatsApp handles key changes is not a “backdoor,” it is how cryptography works. Any attempt to intercept messages in transmit by the server is detectable by the sender, just like with Signal, PGP, or any other end-to-end encrypted communication system.

The only question it might be reasonable to ask is whether these safety number change notifications should be “blocking” or “non-blocking.” In other words, when a contact’s key changes, should WhatsApp require the user to manually verify the new key before continuing, or should WhatsApp display an advisory notification and continue without blocking the user.

Given the size and scope of WhatsApp’s user base, we feel that their choice to display a non-blocking notification is appropriate. It provides transparent and cryptographically guaranteed confidence in the privacy of a user’s communication, along with a simple user experience. The choice to make these notifications “blocking” would in some ways make things worse. That would leak information to the server about who has enabled safety number change notifications and who hasn’t, effectively telling the server who it could MITM transparently and who it couldn’t; something that WhatsApp considered very carefully.

How serious this is depends on your threat model. If you are worried about the US government—or any other government that can pressure Facebook—snooping on your messages, then this is a small vulnerability. If not, then it’s nothing to worry about.

Slashdot thread. Hacker News thread. BoingBoing post. More here.

EDITED TO ADD (1/24): Zeynep Tufekci takes the Guardian to task for their reporting on this vulnerability. (Note: I signed on to her letter.)

EDITED TO ADD (2/13): The vulnerability explained by the person who discovered it.

This is a good explanation of the security/usability trade-off that’s at issue here.

Posted on January 17, 2017 at 6:09 AM • View Comments

Class Breaks

There’s a concept from computer security known as a class break. It’s a particular security vulnerability that breaks not just one system, but an entire class of systems. Examples might be a vulnerability in a particular operating system that allows an attacker to take remote control of every computer that runs on that system’s software. Or a vulnerability in Internet-enabled digital video recorders and webcams that allow an attacker to recruit those devices into a massive botnet.

It’s a particular way computer systems can fail, exacerbated by the characteristics of computers and software. It only takes one smart person to figure out how to attack the system. Once he does that, he can write software that automates his attack. He can do it over the Internet, so he doesn’t have to be near his victim. He can automate his attack so it works while he sleeps. And then he can pass the ability to someone­—or to lots of people—­without the skill. This changes the nature of security failures, and completely upends how we need to defend against them.

An example: Picking a mechanical door lock requires both skill and time. Each lock is a new job, and success at one lock doesn’t guarantee success with another of the same design. Electronic door locks, like the ones you now find in hotel rooms, have different vulnerabilities. An attacker can find a flaw in the design that allows him to create a key card that opens every door. If he publishes his attack software, not just the attacker, but anyone can now open every lock. And if those locks are connected to the Internet, attackers could potentially open door locks remotely—­they could open every door lock remotely at the same time. That’s a class break.

It’s how computer systems fail, but it’s not how we think about failures. We still think about automobile security in terms of individual car thieves manually stealing cars. We don’t think of hackers remotely taking control of cars over the Internet. Or, remotely disabling every car over the Internet. We think about voting fraud as unauthorized individuals trying to vote. We don’t think about a single person or organization remotely manipulating thousands of Internet-connected voting machines.

In a sense, class breaks are not a new concept in risk management. It’s the difference between home burglaries and fires, which happen occasionally to different houses in a neighborhood over the course of the year, and floods and earthquakes, which either happen to everyone in the neighborhood or no one. Insurance companies can handle both types of risk, but they are inherently different. The increasing computerization of everything is moving us from a burglary/fire risk model to a flood/earthquake model, which a given threat either affects everyone in town or doesn’t happen at all.

But there’s a key difference between floods/earthquakes and class breaks in computer systems: the former are random natural phenomena, while the latter is human-directed. Floods don’t change their behavior to maximize their damage based on the types of defenses we build. Attackers do that to computer systems. Attackers examine our systems, looking for class breaks. And once one of them finds one, they’ll exploit it again and again until the vulnerability is fixed.

As we move into the world of the Internet of Things, where computers permeate our lives at every level, class breaks will become increasingly important. The combination of automation and action at a distance will give attackers more power and leverage than they have ever had before. Security notions like the precautionary principle­—where the potential of harm is so great that we err on the side of not deploying a new technology without proofs of security—will become more important in a world where an attacker can open all of the door locks or hack all of the power plants. It’s not an inherently less secure world, but it’s a differently secure world. It’s a world where driverless cars are much safer than people-driven cars, until suddenly they’re not. We need to build systems that assume the possibility of class breaks—and maintain security despite them.

This essay originally appeared on Edge.org as part of their annual question. This year it was: “What scientific term or concept ought to be more widely known?”

Posted on January 3, 2017 at 6:50 AM • View Comments

Smartphone Secretly Sends Private Data to China

This is pretty amazing:

International customers and users of disposable or prepaid phones are the people most affected by the software. But the scope is unclear. The Chinese company that wrote the software, Shanghai Adups Technology Company, says its code runs on more than 700 million phones, cars and other smart devices. One American phone manufacturer, BLU Products, said that 120,000 of its phones had been affected and that it had updated the software to eliminate the feature.

Kryptowire, the security firm that discovered the vulnerability, said the Adups software transmitted the full contents of text messages, contact lists, call logs, location information and other data to a Chinese server.

On one hand, the phone secretly sends private user data to China. On the other hand, it only costs $50.

Posted on November 18, 2016 at 2:22 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.