IT Security Stack Exchange
IT Security Stack Exchange

Questions tagged [cpu]

51 questions
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AMD SEV - attack through the hypervisor console

AMD SEV enables creating a trusted encrypted VM where the memory of the whole VM is encrypted using cryptographic keys and features on the CPU and thus not visible to the cloud provider (in theory if there is no collusion between the chip provider,…
Pavle V
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How to select a CPU to buy for the best security?

Various versions of Spectre, Meltdown, Foreshadow and ZombieLoad make it quite the jungle trip to navigate which CPUs are affected, how to mitigate them. Right now, my problem is that I need a new computer but I want to make sure that I buy the most…
Teekin
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Why are Protection Rings called rings?

Protection rings are different privilege levels granted to software, with the kernel being the most privileged, applications the least privileged, and drivers somewhere in between. My question is why are they called rings? (as opposed to privilege…
LemonPi
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How to fix Spectre variant 3a and variant 4?e

How I can fix CVE-2018-3640 [rogue system register read] aka 'Variant 3a' and CVE-2018-3639 [speculative store bypass] aka 'Variant 4'? My status for them is VULNERABLE. I have Intel CPU and using kernel 4.17. I read on a site there is a framework…
user183433
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What can give physical access to CPU?

If an attacker has an unlimited physical access to CPU, but does not have access to memory, including RAM, can he attack and gain access to the user's data? I heard the opinion that this is impossible according to the laws of physics, even with an…
Malte
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Does malware ever check CPUID?

CPUID is an instruction that identifies CPU type and features. Has there ever been a case of either targeting or the opposite - ignoring of specific CPUIDs by malware in the wild?
Sir Muffington
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Would an anti-virus software make any other processes consume more CPU?

Would an anti-virus software make any other processes that it scans to consume more CPU? We recently switched to a new Next-Gen, AI based Anti-Virus software. On couple of our Linux servers that runs Java processes, there has been frequent high…
Sreeraj
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Can javascript damage data and hardware?

I once had a script looking like the one below: window.open("SameSiteUrl"); alert("spamspamspam"); it had some strange laggy effects... Anyways, a friend "pranked" me by running the script overnight. My PC had a shutdown timer, but when I went to…
Mister SirCode
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How dangerous is the ME on non-vPro CPUs?

I’ve seen plenty of Intel ME vulnerabilities and other security-related issues with the co-processor. However, most seem to be focusing on the extended ME features available on vPro CPUs, which allow complete remote control and function similarly to…
Robotic Extremeties
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Data Execution Prevention X vs NX

My lecturer posted this in his slides and I have no idea what he is trying to say. I quote from his slide: Windows DEP = Data Execution Prevention Old “X” idea: must allow explicitly, current OS+programs would stop working. The “NX” idea: Never…
user5623335
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How protected mode in CPU is really implemented?

I know what is real and protected mode of cpu execution. But how CPU implements protected mode ? AFAIK cpu does everything what the program says it to do. Where is the protected mode behaviour implemented ? Does OS plays any role in this ?
humble_wolf
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Intel Management Engine vulnerabilities in CPUs without vPro

Intel Management Engine (ME) imposes a security risk (see here for example). As I understand ME is a part of Intel vPro. Does having an Intel CPU without vPro support mean ME is not fully functional and hence less vulnerable? I've seen multiple…
raindev
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What is the latest version of ThinkPad laptops that doesn't have Intel Management Engine or similar remote controller built-in?

I work in cybersecurity and would like to find an older laptop that doesn't have the Intel Management Engine built-in, while still able to run a Debian OS well. I have an IBM ThinkPad t42 with 42T0273 system board laying around, which was introduced…
Eduard
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Is it possible to debunk Intel Management Engine conspiracy theories using a data usage monitor device?

If there would be any backdoor in recent Intel CPU's, then it should send and receive data secretly. Isn't it possible to easily debunk this conspiracy theory by implementing a third physical device between the computer and the router to find out if…
Steve
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are small SOC chips also affected by Meltdown and Spectre?

How can I find out, if given CPU is affected by the Meltdown and Spectre bugs ? My CPU is relatively older, and it is a SOC chip: AMD GX-412TC SOC I was not able to find, whether these chips also use speculative…
400 the Cat
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