Re: Troff dangerous.

[thorpej () NAS NASA GOV (Jason Thorpe)]

On Sun, 25 Jul 1999 17:29:56 +0600
 CyberPsychotic <mlists () GIZMO KYRNET KG> wrote:

> ~ If you want your system safe,
> ~ don't look as root
> ~ at manual page.
> ~
>
>  with accurately set permissions for man page directories, non-privileged
> users shouldn't be able to add manual pages to the system (if they are
> able to, system is whacked anyway), so I take this threat merely as
> another trojan possibility - quite uncommon one indeed.

The trick is that it can get you if you as a system administrator download
some open source program from the Internet, and build and install that
program; such activity often happens as "root", so a couple of scenarios
are possible:

        (1) Root installs the malicious roff source unknowingly.

        (2) During the process of building/installing the program, groff
            is invoked as root to create a pre-formatted version of
            the manual page (a "cat page"), at which point the trojan
            horse does it dirty work.

        -- Jason R. Thorpe <thorpej () nas nasa gov>