RE: Taper

["Stephen J. Turnbull" <nospam [at] sk.tsukuba.ac.jp>]

>>>>> "ps" == Paul Sims <psims [at] lombard.co.uk> writes:

    ps> The advice is snipped direct from the FAQ.

Which FAQ?  Taper's?  Do you believe every hack you read about in a
FAQ is a good idea?  It is really common for application programmers
to subvert best practice in favor of convenience.  In this case it's
OK as far as I can tell, as I already said; I just wanted to point out
that as a general matter it's not a good idea to subvert PATH
restrictions, especially if you don't understand the rationale.  And
when you do so, you should leave a trace behind so that you or another
admin will be able to figure out that was done.

Furthermore, it's a simple solution with obvious generalization to
similar situations; but those might involve security or administrative
problems.

A classic example of this is the default setting of SEARCH_HERE_FIRST
in Ghostscript.  From the 6.01 Makefile (I first bitched about this in
Ghostscript 2.4.1, btw, and Peter gave me a clearly well-rehearsed
response very similar to the comment, so I was by no means the first):

# Define whether or not searching for initialization files should always
# look in the current directory first.  This leads to well-known security
# and confusion problems, but users insist on it.
# NOTE: this also affects searching for files named on the command line:
# see the "File searching" section of Use.htm for full details.
# Because of this, setting SEARCH_HERE_FIRST to 0 is not recommended.

SEARCH_HERE_FIRST=1

I have actually seen a personal data retrieval exploit for this,
packaged as initialization code in a PDF file.  (It was constructed by
one of the "good guys," not found in the wild.)  I think you might be
able to find it on CERT somewhere, but I don't remember where I saw
it.

Once again, the security argument doesn't apply to taper, as I already
pointed out indirectly.  There's no real reason not to move stuff
between bin and sbin on an FHS-conformant system.  But that might not
be true where the admin wanted to try to enforce "security through
obscurity".


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