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Re: Shell wildcards considered dangerous?


From: Noel Kuntze <noel.kuntze+oss-security@thermi.consulting>
Date: Mon, 9 Dec 2019 16:28:35 +0100

Hello Leonid,

The message was about the attack vector on applications that put together argument vectors
based on user input, not specifically about human use of the shell.

The same problem applies to that though. Users need to use -- to terminate the option list.

Kind regards

Noel

Am 09.12.19 um 16:18 schrieb Leonid Isaev:
On Mon, Dec 09, 2019 at 03:42:47PM +0100, Noel Kuntze wrote:
That is only a problem if the developer(s) foolishly didn't use "--" to
terminate the command line options or they did, but the argument parser of
the called program does not understand that "--" is a command line option
terminator.
I'm sorry, but this has nothing to do with developers of PROGRAM to use or not
user "--", but rather with the user not properly sanitizing the input to the
PROGRAM and not understanding how shell works. Specifically, doing
PROGRAM *.tar is just asking for trouble for many reasons, not mentioned in the
original email. See [1] (and in general BashPitfalls) for a proper discussion...

HTH,
L.

[1] https://mywiki.wooledge.org/BashPitfalls#for_f_in_.24.28ls_.2A.mp3.29


-- 
Noel Kuntze
IT security consultant

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