Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Application Security //

Ransomware

3/5/2019
06:00 AM
Larry Loeb
Larry Loeb
Larry Loeb
50%
50%

Boosted Rowhammer & Cache Attacks Spell Bad News for Intel

Researchers from Worcester Polytechnic Institute in Massachusetts and the University of Lubeck in Germany have published a paper that is really bad news for Intel.

Researchers from Worcester Polytechnic Institute in Massachusetts and the University of Lübeck in Germany have published a paper, "SPOILER: Speculative Load Hazards Boost Rowhammer and Cache Attacks," that is really bad news for Intel.

It outlines an attack similar to that of Spectre and Meltdown in that it is based the results of speculative execution in a CPU, but on a different set of registers than the first ones use. Here, the Memory Order Buffer is targeted. The MOB is coupled with a CPU cache to manage memory operations.

The researchers found that only Intel CPU chips are vulnerable to this attack. Arm and AMD CPUs are not affected.

The dependency resolution logic that serves the speculative load in the CPU can be exploited to gain information about the physical page mappings that are associated with that load. This is what Rowhammer and cache attacks do in order to obtain a reverse engineering of the virtual-to-physical address mapping.

Worse for Intel, they improved the Rowhammer attack by showing how SPOILER -- the name they gave this class of attack -- helps to conduct DRAM row conflicts deterministically with up to 100% chance, and by demonstrating a double-sided Rowhammer attack with normal user's privilege.

Intel uses a proprietary memory disambiguation and dependency resolution logic in the processors to predict and resolve false dependencies that are related to the speculative load. This makes the speculation results happen faster by not wasting time on intermediate results.

The researchers discovered a false dependency in this process that happens during the 1 MB aliasing of speculative memory accesses which is exploited to leak information about physical page mappings. They note in their paper that, "The leakage can be exploited by a limited set of instructions, which is visible in all Intel generations starting from the1st generation of Intel Core processors, independent of the OS and also works from within virtual machines and sandboxed environments."

So, the root cause for SPOILER is a weakness in the address speculation of Intel's proprietary implementation of the memory subsystem which directly leaks timing behavior due to physical address conflicts.

Oh man, that is a total loss for Intel.

It will make Rowhammer and cache attacks easier, as well as making JavaScript-enabled attacks more feasible.

Mitigation solutions already worked out for Spectre and Meltdown won't work for SPOILER, even though they are both side-channel types of attacks.

The researchers also state that, "There is no software mitigation that can completely erase this problem... The hardware design for the memory disambiguator may be revised to prevent such physical address leakage, but modifying the speculative behavior may cause performance impacts. For instance, partial address comparison was a design choice for performance. Full address comparison may address this vulnerability, but will also impact performance."

Intel is not panicking yet. In a prepared statement given to The Register, they said, "Intel received notice of this research, and we expect that software can be protected against such issues by employing side channel safe software development practices. This includes avoiding control flows that are dependent on the data of interest. We likewise expect that DRAM modules mitigated against Rowhammer style attacks remain protected."

This isn't done yet, not by a long shot.

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 7/6/2020
Ripple20 Threatens Increasingly Connected Medical Devices
Kelly Sheridan, Staff Editor, Dark Reading,  6/30/2020
DDoS Attacks Jump 542% from Q4 2019 to Q1 2020
Dark Reading Staff 6/30/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
How Cybersecurity Incident Response Programs Work (and Why Some Don't)
This Tech Digest takes a look at the vital role cybersecurity incident response (IR) plays in managing cyber-risk within organizations. Download the Tech Digest today to find out how well-planned IR programs can detect intrusions, contain breaches, and help an organization restore normal operations.
Flash Poll
The Threat from the Internetand What Your Organization Can Do About It
The Threat from the Internetand What Your Organization Can Do About It
This report describes some of the latest attacks and threats emanating from the Internet, as well as advice and tips on how your organization can mitigate those threats before they affect your business. Download it today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-5595
PUBLISHED: 2020-07-07
TCP/IP function included in the firmware of Mitsubishi Electric GOT2000 series (CoreOS with version -Y and earlier installed in GT27 Model, GT25 Model, and GT23 Model) contains a buffer overflow vulnerability, which may allow a remote attacker to stop the network functions of the products or execute...
CVE-2020-5596
PUBLISHED: 2020-07-07
TCP/IP function included in the firmware of Mitsubishi Electric GOT2000 series (CoreOS with version -Y and earlier installed in GT27 Model, GT25 Model, and GT23 Model) does not properly manage sessions, which may allow a remote attacker to stop the network functions of the products or execute a mali...
CVE-2020-5597
PUBLISHED: 2020-07-07
TCP/IP function included in the firmware of Mitsubishi Electric GOT2000 series (CoreOS with version -Y and earlier installed in GT27 Model, GT25 Model, and GT23 Model) contains a null pointer dereference vulnerability, which may allow a remote attacker to stop the network functions of the products o...
CVE-2020-5598
PUBLISHED: 2020-07-07
TCP/IP function included in the firmware of Mitsubishi Electric GOT2000 series (CoreOS with version -Y and earlier installed in GT27 Model, GT25 Model, and GT23 Model) contains an improper access control vulnerability, which may which may allow a remote attacker tobypass access restriction and stop ...
CVE-2020-5599
PUBLISHED: 2020-07-07
TCP/IP function included in the firmware of Mitsubishi Electric GOT2000 series (CoreOS with version -Y and earlier installed in GT27 Model, GT25 Model, and GT23 Model) contains an improper neutralization of argument delimiters in a command ('Argument Injection') vulnerability, which may allow a remo...