Re: Re: More Ghostscript Issues: Should we disable PS coders in policy.xml by default?

[Tavis Ormandy <taviso () google com>]

Quick update, this
<http://git.ghostscript.com/?p=ghostpdl.git&a=commitdiff&h=5812b1b78fc4>
commit fixes that problem, but I noticed that fix is incomplete and can be
bypassed, so filed another bug for that (the new bug is 699718).

$ ./gs -dSAFER bug699718.txt
GPL Ghostscript GIT PRERELEASE 9.25 (2018-09-03)
Copyright (C) 2018 Artifex Software, Inc.  All rights reserved.
This software comes with NO WARRANTY: see the file PUBLIC for details.
uid=1000(taviso) gid=1000(primarygroup)


I would like to re-emphasize that while Ghostscript is very capable and
mature software, I consider the -dSAFER sandbox to be a fragile security
boundary and that we should consider deprecating (or minimizing the use of)
untrusted postscript.

Tavis.


On Tue, Sep 4, 2018 at 1:08 PM Tavis Ormandy <taviso () google com> wrote:

> On Tue, Sep 4, 2018 at 1:03 PM Brandon Perry <bperry.volatile () gmail com>
> wrote:
>
> > > On Sep 4, 2018, at 2:59 PM, Tavis Ormandy <taviso () google com> wrote:
> > >
> > > OK, well, the fixes missed 9.24 so vendors will have to either ship
> > patches
> > > once they land or wait for 9.25.
> > >
> > > $ ./gs -v
> > > GPL Ghostscript 9.24 (2018-09-03)
> > > Copyright (C) 2018 Artifex Software, Inc.  All rights reserved.
> > > $ ./gs -q -dSAFER -sDEVICE=ppmraw -f testcase.ps
> > > uid=1000(taviso) gid=1000(taviso)
> > >
> > > Let me know if anyone wants that testcase.
> >
> > Hey Tavis, could I have a copy of the test case please? Thanks so much.
>
> Sure, here it is.
>
> Thanks, Tavis.