Re: [dev] What is bad with Python

From: <random832_AT_fastmail.us>
Date: Thu, 13 Mar 2014 09:05:34 -0400

On Wed, Mar 12, 2014, at 15:04, FRIGN wrote:
> Impressive, but better use
> $ LD_TRACE_LOADED_OBJECTS=1 t
> instead of
> $ ldd t
> next time to prevent arbitrary code-execution[1] in case you're dealing
> with unknown binaries.

I don't know if it was here and you or somewhere else or someone else,
but someone said this before and I pointed out the problems with this
argument. It's even worse in this case because you propose using
LD_TRACE_LOADED_OBJECTS=1 t [which won't actually work, incidentally,
without . in PATH] instead of LD_TRACE_LOADED_OBJECTS=1
/lib/ld-linux.so.2 ./t - your proposed command doesn't actually prevent
the exploit (it actually makes it easier, by making it possible to
exploit with a mere statically-linked program rather than a fancy ELF
interpreter trick)

Also, wanting to do this with an unknown, untrusted executable is, in
practice, _incredibly rare_. And since this is an executable he just
built himself, it obviously doesn't apply here. The 'safe' command
[which, remember, you got wrong] is onerously long for a suggestion that
people should use every time. Maybe the best way forward is to make ldd
default to the safe way and require user confirmation (with a warning)
before the unsafe one.
Received on Thu Mar 13 2014 - 14:05:34 CET