Security News
Most computer systems are still very easy to hack, due to a vulnerability in memory chips produced by Samsung, Micron and Hynix, according to a study by researchers from VUSec of the Vrije Universiteit Amsterdam. The vulnerability in question is called Rowhammer, a design flaw in the internal memory chips of a device that creates the vulnerability.
Intel has posted a fresh crop of firmware updates for security flaws in its chipsets. An information-disclosure flaw in data forwarding for Intel processors prompted an advisory and firmware update, as did the already disclosed LVI design flaw.
Chipzilla's processors, already weighed down by defenses deployed against side-channel attacks over the past two years, could get slower still if they try to thwart this latest vulnerability: prototype compiler changes, for full mitigation, have produced performance reductions ranging from 2x to 19x. That's because LVI protection involves compiler and assembler updates that insert extra x86 instructions and replace problematic instructions with functionally equivalent but more verbose instruction sequences. "Being essentially a 'reverse Meltdown'-type attack, LVI abuses that a faulting or assisted load instruction executed within a victim domain does not always yield the expected result, but may instead transiently forward dummy values or data from various microarchitectural buffers."
Chipzilla's processors, already weighed down by defenses deployed against side-channel attacks over the past two years, could get slower still if they try to thwart this latest vulnerability: prototype compiler changes, for full mitigation, have produced performance reductions ranging from 2x to 19x. That's because LVI protection involves compiler and assembler updates that insert extra x86 instructions and replace problematic instructions with functionally equivalent but more verbose instruction sequences. "Being essentially a 'reverse Meltdown'-type attack, LVI abuses that a faulting or assisted load instruction executed within a victim domain does not always yield the expected result, but may instead transiently forward dummy values or data from various microarchitectural buffers."
Remember rowhammer vulnerability? A critical issue affecting modern DRAM chips that could allow attackers to obtain higher kernel privileges on a targeted system by repeatedly accessing memory cells and induce bit flips. To mitigate Rowhammer vulnerability on the latest DDR4 DRAM, many memory chip manufacturers added some defenses under the umbrella term Target Row Refresh that refreshes adjacent rows when a victim row is accessed more than a threshold.
Remember rowhammer vulnerability? A critical issue affecting modern DRAM chips that could allow attackers to obtain higher kernel privileges on a targeted system by repeatedly accessing memory cells and induce bit flips. To mitigate Rowhammer vulnerability on the latest DDR4 DRAM, many memory chip manufacturers added some defenses under the umbrella term Target Row Refresh that refreshes adjacent rows when a victim row is accessed more than a threshold.
AMD processors sold between 2011 and 2019 are vulnerable to two side-channel attacks that can extract kernel data and secrets, according to a new research paper. In a paper [PDF] titled, "Take A Way: Exploring the Security Implications of AMD's Cache Way Predictors," six boffins - Moritz Lipp, Vedad Hadžić, Michael Schwarz, and Daniel Gruss, Clémentine Maurice, and Arthur Perais - explain how they reverse-engineered AMD's L1D cache way predictor to expose sensitive data in memory.
AMD processors sold between 2011 and 2019 are vulnerable to two side-channel attacks that can extract kernel data and secrets, according to a new research paper. In a paper [PDF] titled, "Take A Way: Exploring the Security Implications of AMD's Cache Way Predictors," six boffins - Moritz Lipp, Vedad Hadžić, Michael Schwarz, and Daniel Gruss, Clémentine Maurice, and Arthur Perais - explain how they reverse-engineered AMD's L1D cache way predictor to expose sensitive data in memory.
AMD is seeking to downplay side-channel attacks that can leak potentially sensitive data from its processors released between 2011 and 2019. AMD this weekend said it does not believe these are "New speculation-based attacks" and did not offer any mitigations: "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," said AMD in a Saturday advisory.
AMD is seeking to downplay side-channel attacks that can leak potentially sensitive data from its processors released between 2011 and 2019. AMD this weekend said it does not believe these are "New speculation-based attacks" and did not offer any mitigations: "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," said AMD in a Saturday advisory.