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Re: Troff dangerous.
From: ronny () TMX COM AU (Ronny Cook)
Date: Mon, 26 Jul 1999 12:23:30 +1000
Date: Sun, 25 Jul 1999 10:18:20 -0400
From: John Robert LoVerso <john () LOVERSO SOUTHBOROUGH MA US>
This isn't a problem with "troff" or any of it's varients. Instead,
this is an exploit purely with "groff", the GNU reimplementation. Troff
doesn't have the file stream or ".pso" requests; those are purely part
Thus, this affects only systems with groff installed (all Linux and FreeBSD
systems, at least).
The original nroff had a ".pi" command (which only worked for nroff, not
troff). It pipes the output of the nroff command to a particular program,
although no command line arguments could be supplied. (This is according to
the "Nroff/Troff User's Manual", section 19: "Input/Output File Switching".)
I agree it's a concern, although having the man pages writable in the
first place is something of a risk if you ask me... I would think that the
principle of least privilege would apply.
Ronald Cook, Technical Manager - Message Handling Systems/The Message eXchange
Email: ronny () tmx com au ----- Phone: +61-2-9550-4448 ---- Fax: +61-2-9519-2551
- Re: Troff dangerous., (continued)