Jul 12 2018

Microsoft offers extended support for Windows, SQL 2008—but with a catch

(credit: Marcus W / Flickr)

Windows Server 2008 and 2008 R2, as well as SQL Server 2008 and 2008 R2, are due to move out of extended support over the next few years—SQL Server in July 2019 and Windows Server in January 2020. For organizations still using that software, this offers a few options: keep using the software and accept that it won't receive any more security updates, migrate to newer equivalents that are still supported, or pay Microsoft for a custom support contract to continue to receive security updates beyond the cutoff dates.

Today, Microsoft added a fourth option: migrate to Azure. Microsoft is extending the support window by three years (until July 2022 for SQL Server, January 2023 for Windows Server) for workloads hosted on Azure in the cloud. This extended support means that customers that make the switch to the cloud will receive another three years of security fixes. After those three years are up, customers will be back to the original set of choices: be insecure, upgrade, or pay for a custom support contract.

Microsoft isn't requiring customers to demonstrate that they have any kind of migration plan in place, and this support scheme incurs no additional costs beyond those already imposed by running software on Azure in the first place.

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Jul 10 2018

New Spectre-like attack uses speculative execution to overflow buffers

Enlarge (credit: Aurich Lawson / Getty Images)

When the Spectre and Meltdown attacks were disclosed earlier this year, the expectation was that these attacks would be the first of many, as researchers took a closer look at the way that the speculative execution in modern processors could be used to leak sensitive information and undermine the security of software running on those processors. In May, we saw the speculative store bypass, and today we have a new variant on this theme: speculative buffer overflows, discovered by Vladimir Kiriansky at MIT and independent researcher Carl Waldspurger.

All the attacks follow a common set of principles. Each processor has an architectural behavior (the documented behavior that describes how the instructions work and that programmers depend on to write their programs) and a microarchitectural behavior (the way an actual implementation of the architecture behaves). These can diverge in subtle ways. For example, architecturally, a program that loads a value from a particular address in memory will wait until the address is known before trying to perform the load. Microarchitecturally, however, the processor might try to speculatively guess at the address so that it can start loading the value from memory (which is slow) even before it's absolutely certain of which address it should use.

If the processor guesses wrong, it will ignore the guessed-at value and perform the load again, this time with the correct address. The architecturally defined behavior is thus preserved. But that faulty guess will disturb other parts of the processor—in particular the contents of the cache. These microarchitectural disturbances can be detected and measured, allowing a malicious program to make inferences about the values stored in memory.

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Jun 25 2018

Hyperthreading under scrutiny with new TLBleed crypto key leak

Enlarge / A shiny wafer full of Kaby Lake refresh parts. (credit: Intel)

Last week, developers on OpenBSD—the open-source operating system that prioritizes security—disabled hyperthreading on Intel processors. Project leader Theo de Raadt said that a research paper due to be presented at Black Hat in August prompted the change, but he would not elaborate further.

The situation has since become a little clearer. The Register reported on Friday that researchers at Vrije Universiteit Amsterdam in the Netherlands have found a new side-channel vulnerability on hyperthreaded processors that's been dubbed TLBleed. The vulnerability means that processes that share a physical core—but which are using different logical cores—can inadvertently leak information to each other.

In a proof of concept, researchers ran a program calculating cryptographic signatures using the Curve 25519 EdDSA algorithm implemented in libgcrypt on one logical core and their attack program on the other logical core. The attack program could determine the 256-bit encryption key used to calculate the signature with a combination of two milliseconds of observation, followed by 17 seconds of machine-learning-driven guessing and a final fraction of a second of brute-force guessing.

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Jun 25 2018

Hyperthreading under scrutiny with new TLBleed crypto key leak

Enlarge / A shiny wafer full of Kaby Lake refresh parts. (credit: Intel)

Last week, developers on OpenBSD—the open-source operating system that prioritizes security—disabled hyperthreading on Intel processors. Project leader Theo de Raadt said that a research paper due to be presented at Black Hat in August prompted the change, but he would not elaborate further.

The situation has since become a little clearer. The Register reported on Friday that researchers at Vrije Universiteit Amsterdam in the Netherlands have found a new side-channel vulnerability on hyperthreaded processors that's been dubbed TLBleed. The vulnerability means that processes that share a physical core—but which are using different logical cores—can inadvertently leak information to each other.

In a proof of concept, researchers ran a program calculating cryptographic signatures using the Curve 25519 EdDSA algorithm implemented in libgcrypt on one logical core and their attack program on the other logical core. The attack program could determine the 256-bit encryption key used to calculate the signature with a combination of two milliseconds of observation, followed by 17 seconds of machine-learning-driven guessing and a final fraction of a second of brute-force guessing.

Read 19 remaining paragraphs | Comments