New AMD Side Channel Vulnerabilities found

Over the weekend a new report surfaced online, indicating that AMD would have Side Channel Vulnerabilities in their processors. The paper released by the Graz University of Technology detailed two new "Take A Way" attacks, Collide+Probe and Load+Reload, that can leak secret data from AMD processors by manipulating the L1D cache predictor.

The researchers claim that the vulnerability impacts all AMD processors from 2011 to 2019. The research team said it notified AMD about the two problems in August 2019, however, the company has not publicly addressed the two problems, nor has it released microcode updates (CPU firmware).

“We reverse-engineered AMD’s L1D cache way predictor in microarchitectures from 2011 to 2019, resulting in two new attack techniques,” the researchers said.

Both exploit the "way predictor" for the Level 1 cache (meant to boost the efficiency of cache access) to leak memory content. The Collide+Probe attack lets an intruder monitor memory access without having to know physical addresses or shared memory, while Load+Reload is a more secretive method that uses shared memory without invalidating the cache line. The team took advantage of the flaws using JavaScript in common browsers like Chrome and Firefox. While Take A Way only exposes out a small amount of information compared to Meltdown or Spectre, that was enough for the investigators to access AES encryption keys. It would be possible to address the flaw through a mix of hardware and software, the researchers said, although it's not certain how much this would affect performance.

AMD posted the following statement on its website

AMD responded to the publication of these security vulnerabilities via a security advisory on its website, acknowledging the security exploits and stating they were not a new form of side-channel attack.

“We are aware of a new white paper that claims potential security exploits in AMD CPUs, whereby a malicious actor could manipulate a cache-related feature to potentially transmit user data in an unintended way,” AMD said.

“The researchers then pair this data path with known and mitigated software or speculative execution side-channel vulnerabilities. AMD believes these are not new speculation-based attacks.”

AMD said it recommended users follow the steps be taken by users to help mitigate against side-channel attacks:

Keep your operating system up-to-date by operating at the latest version revisions of platform software and firmware, which include existing mitigations for speculation-based vulnerabilities
Following secure coding methodologies
Implementing the latest patched versions of critical libraries, including those susceptible to side-channel attacks
Utilizing safe computer practices and running antivirus software

The advisory does not point to any mitigations for the attack in question, merely citing other mitigated speculative executions that were used as a vehicle to attack the L1D cache predictor.

The Graz University of Technology performed a lot of Vulnerability tests ion the past, but the reality is also that they are partially funded by intel, it seems. The paper mentions this, and really, just read it: "Additional funding was provided by generous gifts from Intel. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the funding parties." Albeit a curiosity, the co-authors of the Intel-funded study also revealed Intel's vulnerabilities in the past.

sverek

Posts: 6073
Joined: 2011-01-02

#5767342 Posted on: 03/09/2020 09:58 AM

The Graz University of Technology performed a lot of Vulnerability tests ion the past, but the reality is also that they are partially funded by intel, it seems.

Boy, it gonna be good.

Please AMD and Intel, call out each others holes and secure your shit. I am all for it.

anticupidon

Posts: 6186
Joined: 2008-03-06

#5767345 Posted on: 03/09/2020 10:02 AM

Good to see that security folks are ever vigilant. Now, AMD is having its share of vulnerabilities.
Let's see how this will pan out.

fantaskarsef
Senior Member

Posts: 12426
Joined: 2014-07-21

#5767376 Posted on: 03/09/2020 10:49 AM

Well, everybody gets a security problem for free with speculative execution. Maybe that's a generally dangerous way of creating CPU architectures... I wonder if they will be searching for an alternative route down the way.

Boy, it gonna be good.

While I agree with you as usual, the full paragraph tells more than the first line:

Kaarme
Senior Member

Posts: 2559
Joined: 2013-03-10

#5767392 Posted on: 03/09/2020 11:28 AM

It's pretty hard to take seriously an Intel funded study on AMD CPUs, but it's not like we wouldn't have known AMD's CPUs have their own vulnerabilites. They are just far less numerous than Intel's.

skimike
Junior Member

Posts: 2
Joined: 2020-02-10

#5767411 Posted on: 03/09/2020 12:53 PM

Everything I have seen about this vulnerability since it popped up last Friday suggests that it leaks metadata rather than actual data. Has anyone read anything to the contrary?

New AMD Side Channel Vulnerabilities found - AMD Reacts and Downplays

AMD posted the following statement on its website