Always about Security Patching and Updates

These days I keep coming back to the “security patching and updates” issue. So I am going to add another couple of comments.

The first is about Ripple 20 (here the official link but the news is already wide spread) which carries an impressive number of “CVSS v3 base score 10.0” vulnerabilities. The question is again:

how can we secure all of these Million/Billion vulnerable devices since it seems very likely that security patching is not an option for most of them?

The second one is very hypothetical, that is in the “food for thought” class.

Assume, as some says, that in 2030 Quantum Computers will be powerful enough to break RSA and other asymmetrical cryptographic algorithms, and that at the same time (or just before) Post Quantum Cryptography will deliver us new secure algorithms to substitute RSA and friends. At first sight all looks ok: we will have just to do a lot of security patching/updating of servers, clients, applications, CA certificates, credit cards (hardware), telephone SIMs (hardware), security keys (hardware), Hardware Security Modules (HSM) and so on and on… But what about all those micro/embedded/IoT devices in which the current cryptographic algorithms are baked into? And all of those large devices (like aircrafts but also cars) which have been designed with cryptographic algorithms baked into them (no change possible)? We will probably have to choose between living dangerously or buy a new one. Or we could be forced to buy a new one, if the device will not be able to work anymore since its old algorithm will not be accepted by the rest of the world.

PS. Concerning Quantum Computers,  as far as I know nobody claims that a full Quantum Computer will be functioning by 2030, this is only the earliest possible estimate of arrival, but it could take much much longer, or even never!

PS. I deliberately do not want to consider the scenario in which full Quantum Computers are available and Post Quantum Cryptography is not.

On the Latest Bluetooth Impersonation Attack

Details on a new attack on Bluetooth have just been released (see here for its website). From what I understand it is based on two weaknesses of the protocol itself.

A quick description seems to be the following (correct me if I have misunderstood something).

When two Bluetooth devices (Alice and Bob) pair, they establish a common secret key mutually authenticating each other. The secret common key is kept by both Alice and Bob to authenticate each other in all future connections. Up to here all is ok.

Now it is important to notice the following points when Alice and Bob establish a new connection after pairing:

  • the connection can be established using a “Legacy Secure Connection” (LSC, less secure) or a “Secure Connection” (SC, secure), and either Alice or Bob can request to use LSC;
  • one of the devices acts as Master and the other as Slave, a connection can be closed and restarted and either Alice or Bob can request to act as Master;
  • in a “Legacy Secure Connection” the Slave must prove to the Master that it has the common secret key, but it is not requested that the Master proves to the Slave that it also has the common secret key (Authentication weakness);
  • in a “Secure Connection” either Alice or Bob can close the connection and restart it as a “Legacy Secure Connection” (Downgrade weakness).

Now Charlie wants to intercept the Bluetooth connection between Alice and Bob: first he listens to their connection and learns their Bluetooth addresses (which are public). Then Charlie jams the connection between Alice and Bob and connects as a Master to Alice using LSC and Bob’s Bluetooth address, and connects as a Master to Bob using LSC and Alice’s Bluetooth address. Since Charlie is Master both with respect to Alice and to Bob and since he can always downgrade the connection to LSC, he does not have to prove to neither Alice or Bob that he knows their common secret key. In this way Charlie is able to perform a MitM attack on the Bluetooth connection between Alice and Bob (obviously this description is very high level, I sketched just an idea of what is going on).

The bad point about this is that it is a weakness of the protocol, so all existing Bluetooth implementations are subject to it. The good point is that the fix should not be too difficult, except for the fact that many (too many) devices cannot be patched! Fortunately this attack seems not to apply to Bluetooth LE, but still I expect that most Bluetooth devices subject to this attack will never be patched.

But we should also consider the real impact of this attack: to perform it, the attacker Charlie should be physically near enough to the two devices (Alice and Bob) with a dedicate hardware (even if not so expensive), so this limits the possible implementations. Moreover this attack can have important consequences if Bluetooth is used to transfer very sensitive information or for critical applications (for example in the health sector). In other words, I would not worry when using Bluetooth to listen to music from my smartphone but I would worry if Bluetooth is used in some mission critical applications.

Whats’s happening in Cyber/IT Security?

Comparing current reported cyber/IT security threats, attacks and incidents to what happened a few years ago, it seems to me that  something has surely changed (I must warn that these conclusions are not based on statistics but on reading everyday bulletins and news).

On one side, security surely has improved: vulnerabilities are reported and fixed, patches are applied (at least more often), security policies, standards and practices are making a difference. Still managing password and properly configuring systems and services exposed on Internet remain very difficult tasks too often performed without the required depth.

But security has improved, which also means that attackers have been moving to easier and more lucrative approaches which have to do mostly with the “human interface”. In other words: fraud.

The first example is ransomware, that is the attacker is able to access the victim system, copy vast amount of data, then encrypt it or remove it and finally ask a ransom not only to return the data but also to avoid making it public on Internet. Since everybody is getting better in making backups, here the important point is the “making it public on Internet” so that the ransom is asked more to prevent sensitive data to be published than to restore the systems.

The second example is Targeted Phishing attacks, Business Email Compromise and similar scams in which the attacker impersonate a well known or important person by writing emails, letters, making phone calls etc. to convince typically a clerk but in some cases also a manager, to send a large amount of money to the wrong bank account.

Neither of these two types of attacks is new, but now they are filling the news daily. Even if cyber/IT security can still improve tremendously, there have been and there are notable security improvements which makes it that attacks are aimed more often to the weakest link: the human user.

Another Nail in the Coffin of SHA1

A few days ago, a new attack has been made public which makes it easier to forge hash (or “message digests”) computed with SHA1 (see for example this article for more details).

This new collision attack makes it faster and less expensive to create two documents with the same digital signature using SHA1 or, having a digitally signed document where the digital signature uses SHA1 as hash algorithm, to create a different second document which has the same digital signature.

It has been known since a few years that SHA1 is broken and that it should not be used for digital signatures and in general for security purposes (actually NIST suggested to stop using SHA1 already in 2012). But as usual, in the real world there are still many, too many legacy applications which today continue to use SHA1, one example being legacy PGP keys and old PGP digital signatures.

This new result should be at least a useful reminder to all of us to check if we are still using SHA1 in some applications and in case finally update it.

Patching timing is getting tight

The US Cybersecurity and Infrastructure Security Agency (CISA) has recently reviewed the guidelines (actually a Binding Operational Directive for US Federal Agencies) on patching (see the Directive here and a comment here).

Now vulnerabilities rated “critical” (according to CVSS version 2) must be remediated within 15 days (previously it was 30 days) and “high” vulnerabilities within 30 days from the date of initial detection by CISA weekly scanning.

Due to the short time between detection and remediation of vulnerabilities, applying patches in time is going to be difficult, due to the possibily missing availability of patches by the vendors and the time needed anyway to test them in each IT environment.

This implies that there must be in place processes to design, test and deploy temporary countermeasures to minimize to an acceptable level the risks due to these vulnerabilities. And these processes must be fast, they should take at most a few days.

AutoCAD malware

Recently I have paid some attention to AutoCAD and similar software. Not that I use them or that know much about them, but it definitively striked me both the complexity and the amazing features that some of these applications have. But with complexity, large number of features and dimension of code, come also vulnerabilities, even security vulnerabilities.

A few days ago I noticed this article (here a less technical summary) about AutoCAD malware, which has been around for more than 10 years. The purpose of this malware can be twofold: just another malware infecting channel, or more likely, a very targeted attack channel. Indeed CAD software is used for designing buildings, bridges, tunnels, roads etc., and some blueprints can be worth millions. Companies have taken notice of this, and security features have been introduced in the applications.

But the issue which does not seem to be appreciated enough (I have no statistics though, so I can be wrong on this) is the patching process (and this is not limited to CAD software but applies to other specialised software as for example digital audio or gaming). It seems to me that some of these applications are seldom updated (one needs to download/buy a new version) or that security patches are bundled together with new functionalities which can come at a cost, at least after the initial few years of support.

In my opinion, in an ideal world security patches should be provided for free to anyone until the program is supported. Obviously this can have economical impacts on the company producing the software and could require changes in the way software is built, sold and distributed (costs again).

Hardware Vulnerabilities (Again), Cloud and Mobile Security

Have a very Happy New Year!

… and to start 2017 on a great note, I write again about Hardware Vulnerabilities with comments on Cloud and Mobile Security.

The opportunity for this blog entry has been provided to me by the talk “What could possibly go wrong with <insert x86 instruction here>? Side effects include side-channel attacks and bypassing kernel ASLR” by Clémentine Maurice and Moritz Lipp at Chaos Computer Club 2016 which I suggest to watch (it lasts 50 minutes and it is not really technical despite its title).

A super-short summary of the talk is that it is possible to mount very effective side- (in particular time-) channel attacks on practically any modern Operating System which allow to extrafiliate data, open communication channel and spy on activities like keyboards inputs. All of this using only lecit commands and OS facilities, but in some innovative ways.

The reason for which these attacks are possibile is that the hardware does not prevent them, actually some hardware features, added to improve performances, make these attacks easier or even possible (see also my previous post on Hardware Vulnerabilities about this). So from the Security point of view these Hardware features should be considered as Vulnerabilities.

What is it possible to do with these techniques? Considering Cloud, it is possible to monitor the activities of another Virtual Machine running on the same hardware, extract secrect cryptography keys (but this depends on how the algorithm and protocols are implemented), establish hidden communication channels etc.

Similarly for Mobile, it is possible to have a totally lecit App to monitor the keyboard activity, or 2 Apps to establish a hidden communication so that one reads some data and the other sends it to a remote destination, all without violating any security rule (actually each one having very limited privilegies and restricted setups).

Morevoer it seeems easy to embed this kind of attacks in lecit applications and current anti-virus seem to lack the capabilities needed to intercept them. Indeed the activites performed to implement these attacks look almost identical to the ones performed by any program and it seems that only a particular performance monitoring could discover them.


On Denial of Service attacks and Hardware vulnerabilities

Denial of Service attacks are growning and getting the attention of the news: some of the latest incidents are krebonsecurity , OVH and Dyn. The economics behind these attacks are helping the attackers: today it costs little to mount a devastating DDoS attack able to block even a sizable part of Internet, thanks to all the botnets of unsafe machines, from PCs to routers and IoTs. Defence can be much more expensive than attack, and in some cases even than the ransom.

How did we get in this mess? This trend is not good at all, these attacks could threaten Internet itself, even if this would not be in the interest of the attackers (not considering State sponsored ones).

Fixing the current situation will be extremely expensive, many devices cannot be “fixed” but need just to be replaced. But before doing that, we need to build “secure” devices and design networks and protocols that support them and are somehow interoperable with the current ones. How? And When?

At the same time, a new trend is emerging: security vulnerabilities in Hardware.

The Rowhammer bug and its recent implementations in Virtual machines and Adroid phones (DRAMMER) or the ASLR vulnerability can open new scenarios. Hardware must provide the foundation of the security of all IT processing: data should be protected, accesses should be controlled etc. But we are discovering that the Hardware that we have been relying upon for the development of IT in the last 20 years, could have reached its limits. New security features are needed (see for example this) and vulnerabilities are discovered that must be managed, and not always it will be possible to fix them in software.