What is a row hammer attack?
Rowhammer attacks work by rapidly and repeatedly reading data in one memory row to cause an electrical charge in adjacent memory rows in order to modify or corrupt data.
How does a Rowhammer attack work?
Rowhammer is a vulnerability in commodity dynamic random access memory (DRAM) chips that allows an attacker to exploit devices with DRAM memory by repeatedly accessing (hammering) a row of memory until it causes bit flips and transistors in adjacent rows of memory reverse their binary state: ones turn into zeros and …
How do you stop Rowhammer?
One straightforward solution to mitigate row-hammer is to simply increase the refresh rate for all the rows in the memory system. Although, this approach might alleviate the Row Hammer error, it imposes an unnecessary power and performance overhead to the system.
What is Target row refresh?
Among existing solutions, the leading and most effective example is the Target Row Refresh (TRR) mechanism. TRR is proposed as the standard protection mechanism by JEDEC [1] and is widely used in DDR4 memory. As a protection scheme, TRR will refresh the victim row once a Rowhammer attack is detected.
What is Spectre and meltdown vulnerability?
Vulnerabilities in modern computers leak passwords and sensitive data. Meltdown and Spectre exploit critical vulnerabilities in modern processors . These hardware vulnerabilities allow programs to steal data which is currently processed on the computer.
What is DRAM storage?
Dynamic random access memory (DRAM) is a type of semiconductor memory that is typically used for the data or program code needed by a computer processor to function. DRAM is a common type of random access memory (RAM) that is used in personal computers (PCs), workstations and servers.
How does Spectre and meltdown work?
What are Spectre and Meltdown? In the most basic definition, Spectre is a vulnerability allowing for arbitrary locations in the allocated memory of a program to be read. Meltdown is a vulnerability allowing a process to read all memory in a given system.
Is Rowhammer a side-channel?
Rowhammer is an attack technique involving accessing—that’s “hammering”—rows of bits in memory, millions of times per second, with the intent of causing bits in neighboring rows to flip. This is a side-channel attack, and the result can be all sorts of mayhem.
What is RFM DRAM?
RFM enables the separation of the tasks for RH- protection to both MC and DRAM by having the former generate an RFM command at a specific activation frequency and the latter take proper RH-protection measures within a given time window.
How does Spectre exploit work?
Mechanism. Spectre is a vulnerability that tricks a program into accessing arbitrary locations in the program’s memory space. An attacker may read the content of accessed memory, and thus potentially obtain sensitive data.
What is the difference between Meltdown and Spectre?
In the most basic definition, Spectre is a vulnerability allowing for arbitrary locations in the allocated memory of a program to be read. Meltdown is a vulnerability allowing a process to read all memory in a given system.
What are the three types of DRAM?
DDR2, DDR3, and DDR4 Many HP computers use the DDR series of DRAM chips. The technology improves from one generation to the next, which is indicated by the number series. DDR4, for example, is faster and more efficient than DDR2 or DDR3.
What is DRAM vs SRAM?
SRAM: is a memory chip that is faster and uses less power than DRAM. DRAM: is a memory chip that can hold more data than an SRAM chip, but it requires more power. First, some background. Random access memory (RAM) is a semiconductor device placed on a processor that stores variables for CPU calculations.
Has Spectre been fixed?
In March 2018, Intel announced that they had developed hardware fixes for Meltdown and Spectre-V2 only, but not Spectre-V1. The vulnerabilities were mitigated by a new partitioning system that improves process and privilege-level separation.
Has Spectre been exploited?
A fully weaponized exploit for the Spectre CPU vulnerability was uploaded on the malware-scanning website VirusTotal last month, marking the first time a working exploit capable of doing actual damage has entered the public domain. The exploit was discovered by French security researcher Julien Voisin.
What is self refresh in DRAM?
1 DRAM requirements for self-refresh DDR DRAM has a self-refresh mode that can be used to retain data in the DRAM without requiring a processor or memory controller to refresh the data. When in this mode, the DRAM does not require external clocking to retain the data.
What is the difference between Spectre and Meltdown?
How hard is it to exploit Spectre?
Spectre is harder to exploit than Meltdown, but it is also harder to mitigate. However, it is possible to prevent specific known exploits based on Spectre through software patches.
What is a rowhammer attack?
What Does Rowhammer Mean? Rowhammer or row hammer is a type of cyber-attack that exploits a bug in dynamic random-access memory (DRAM) modules manufactured in 2010 and onwards. This vulnerability can even be exploited via JavaScript, allowing an attacker to escape a Web browser’s security sandbox and gain access to the system.
What is rowhammer vulnerability?
Rowhammer or row hammer is a type of cyber-attack that exploits a bug in dynamic random-access memory (DRAM) modules manufactured in 2010 and onwards. This vulnerability can even be exploited via JavaScript, allowing an attacker to escape a Web browser’s security sandbox and gain access to the system.
What is rowhammer in memory array design?
Rowhammer is a defect of the memory array design, not a degradation of the device, although degradation DOES happen it is not related to row hammer. Rowhammer is a problem because it causes corruption of multiple bits in a row.
How can the row hammer effect be prevented?
Different hardware-based techniques exist to prevent the row hammer effect from occurring, including required support in some processors and types of DRAM memory modules. In dynamic RAM (DRAM), each bit of stored data occupies a separate memory cell that is electrically implemented with one capacitor and one transistor.