Re: Ghostscript 8.64 executes random code at startup



Dnia środa, 26 maja 2010 o 04:32:51 paul.szabo@xxxxxxxxxxxxx napisał(a):
Dear Christopher,

Ghostscript_8.64 on openSuSE_11.2 executes all files matching
./Encoding/* on startup. This search is relative to the current
directory so it is easy to poison Ghostscript and cause it to execute
arbitrary PostScript code without user action or knowledge.

Details: <URL:https://bugzilla.novell.com/show_bug.cgi?id=608071>

Interesting! So if someone creates /tmp/Encoding then it is dangerous
to do
cd /tmp; gs any.ps

I now used:
strace -omylog gs
grep '"\./' mylog | sort -u
and that shows that gs tries many files in currrent directory,
"protection" against just ./Encoding is not enough.

What is in the file "any.ps"?

You are exposed to the Encoding vulnerability without feeding *anything* to
Ghostscript:

cd /tmp
gs
Bang!