Questions tagged [meltdown]

A side-channel vulnerability affecting Intel x86 and few ARM-based microprocessors allowing user processes to read memory belonging to the kernel. Affects various OSes like Linux, OS X, and Windows. Published in January 2018.

A side-channel vulnerability affecting Intel x86 and few ARM-based microprocessors allowing user processes to read memory belonging to the kernel. Affects various OSes like Linux, OS X, and Windows. Published in January 2018.

The attack exploits timing differences in out-of-order instruction execution, coupled with a privilege escalation vulnerability specific to Intel processors, due to which speculatively executed instructions can bypass memory protection mechanisms. Meltdown allows user processes to read memory belonging to the kernel or other processes. In particular, it breaks the security between virtual machines running on the same host.

See full attack details at https://meltdownattack.com

See our canonical question on this site at Meltdown and Spectre Attacks

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Why are CPUs designed in a way so the "meltdown" exploit works?

I'm trying to wrap my head around "meltdown", but to first understand it, I've been trying to understand memory accesses. From what I understand, the CPU attempts to look up the virtual address in the translation lookaside buffer, which indicates…
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What do speculative execution patches protect me from?

There are a barrage of patches coming out, both at the application and OS levels for the recently disclosed speculative execution attacks against various vulnerabilities in CPUs from AMD, ARM, and Intel. I don't fully understand the attacks nor am…
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Meltdown - PoC - Reading physical address with KASLR disabled does not work

Working with this PoC https://github.com/IAIK/meltdown Running it: # ./secret [+] Secret: Sample text [+] Virtual address of secret: 0x4af528 [+] Physical address of secret: 0x172bc3528 [+] Exit with Ctrl+C if you are done reading the…
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Can one sidestep Meltdown/Spectre vulnerabilities by not installing new software on a server?

Is it possible to not install new programs on a server and sidestep any Meltdown/Spectre vulnerabilities because it is only a newly identified issue. I have an SLES server that runs a fixed database load. It's an Intel Xeon on AWS (hvm) VPC in a…
Dinesh
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