Can we add "some ancient Via CPUs" to the title. Current title is pure click bait.
Hardware backdoors in some x86 CPUs
11–20 of 102 posts
Re: Hardware backdoors in some x86 CPUs
#12For Intel-ME and AMD PSP, you fundamentally can't see the backdoor they could produce unless you probe the seperate chip lol.
Re: Hardware backdoors in some x86 CPUs
#13"Not this shit again"...
Almost exactly 8 years ago: https://news.ycombinator.com/item?id=17727140
Re: Hardware backdoors in some x86 CPUs
#14This backdoor only appears on decades-old VIA C3 embedded x86 processors
Also worth noting that the exploit was published nearly decade ago. Still, even at that time, those VIA CPUs were over 15 years old.
Re: Hardware backdoors in some x86 CPUs
#15This backdoor only appears on decades-old VIA C3 embedded x86 processors
It's not even a "backdoor", it's documented in the datasheet...
http://datasheets.chipdb.org/VIA/Nehemiah/VIA%20C3%20Nehemia... (page 82)
...which along with the already publicly-known microarchitecture of the C3 makes this statement sound like total nonsense:
The rosenbridge backdoor is a small, non-x86 core embedded alongside the main x86 core in the CPU
I remember laughing at this with a few others knowledgeable in x86 when it first came out; a self-proclaimed "security researcher" who somehow failed to RTFM.
There's even a Wikipedia article about it now, with a link to the alternate instruction set documentation: https://en.wikipedia.org/wiki/Alternate_Instruction_Set
Re: Hardware backdoors in some x86 CPUs
#16Should add (2018) to the title
Re: Hardware backdoors in some x86 CPUs
#17Interesting codenames: https://en.wikipedia.org/wiki/List_of_VIA_C3_microprocessors
Re: Hardware backdoors in some x86 CPUs
#18While the README calls it a separate core, it's more likely to be a direct encoding of uops.
Re: Hardware backdoors in some x86 CPUs
#19This backdoor only appears on decades-old VIA C3 embedded x86 processors
It's not even a "backdoor", it's documented in the datasheet... http://datasheets.chipdb.org/VIA/Nehemiah/VIA%20C3%20Nehemia... (page 82) ...which along with the already publicly-known microarchitecture of the C3 makes this statement sound like total nonsense: The rosenbridge backdoor is a small, non-x86 core embedded alongside the main x86 core in the CPU I remember laughing at this with a few others knowledgeable i…
It's not as clear cut as you describe it here. In the other old thread you linked there was no real consensus if this should be considered a backdoor or not.
Re: Hardware backdoors in some x86 CPUs
#20This shows that large companies making closed-source CPUs cannot be trusted. No doubt they would add whatever the government asks them to add. What can be done to mitigate this? One option would be to buy a large FPGA and flash it with an open-source CPU. Another would be to emulate a CPU, working with encrypted data and commands, so that even if the backdoor in a host CPU tries to overwrite memory, it would only cra…
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