"insecure world writable" fix?

Hello All,

I have come up with a fix/workaround which turns off the “insecure world
writable” warning message.

In my code, I pass a string (exec_str) to exec:

exec_str = "./foo.pl test"
exec(exec_str)

Depending on my PATH, this can point out any number of world-writable
directories on my network.

If I change the above so I’m just adding a CR to the end of exec_str, I
now do not see the warning message any longer:

exec_str = "./foo.pl test\n"
exec(exec_str)

Anyone have an idea why this works?

Thanks,
-Sean

Sean H. wrote:

Depending on my PATH, this can point out any number of world-writable
directories on my network.

If I change the above so I’m just adding a CR to the end of exec_str, I
now do not see the warning message any longer:

exec_str = "./foo.pl test\n"
exec(exec_str)

Anyone have an idea why this works?

Heck of a workaround. Thanks. I look forward to
explanations as to why it works.

I’ve been using this:
exec_str = “eval ‘’; …”

The initial eval also stops the insecure writable
message.

There’s no way to modify the environment, either.
Access ENV. causes the message to appear
before I even try to execute anything in a subshell.

That message is one heckofa mystery, to be sure.

“S” == Sean H. [email protected] writes:

S> exec_str = “./foo.pl test\n”
S> exec(exec_str)

S> Anyone have an idea why this works?

When ruby find some special characters (like \n;[]{} …) in the
string, it
call the shell (/bin/sh -c) rather than trying to exec directly the
program. In this case it don’t test the variable PATH

Guy Decoux

Ok, I understand the reason this works the way it does - Ruby wants the
shell to handle any special characters that may result in
substitutions/matching, etc. That makes sense. But is there an “official
workaround” for this problem? And if not, can I rest well at night with
my ‘\n’ workaround in my companys stable source tree? It’s just a
warning message now, but in the future, I can’t really forsee any
problems with putting a CR at end of exec_str, but…

Thanks,
-Sean

“S” == Sean H. [email protected] writes:

S> substitutions/matching, etc. That makes sense. But is there an
“official
S> workaround” for this problem? And if not, can I rest well at night
with

Yes, correct the problem (i.e. change the permission for the directory)
:slight_smile:

S> my ‘\n’ workaround in my companys stable source tree? It’s just a
S> warning message now, but in the future, I can’t really forsee any

it’s a warning message with $SAFE = 0, but an error with $SAFE >= 1

svg% ruby -e ‘exec(“ls”)’
-e:1: warning: Insecure world writable dir /home/ts/XXX/., mode 040777
svg%

svg% ruby -e ‘$SAFE = 1; exec(“ls”)’
-e:1: warning: Insecure world writable dir /home/ts/XXX/., mode 040777
-e:1:in `exec’: Insecure PATH - ls (SecurityError)
from -e:1
svg%

Guy Decoux

As the ts said, setting the $SAFE is a way to ignore the warning.
Or
run the ruby script like this:
ruby -w0 file…

Last we can change the permission of the dictionary.
For example,
drwxr-xr-x 7 abc abc … /home/abc/bin
Let other users can only access the dictionary.

ts wrote:

“S” == Sean H. [email protected] writes:

S> substitutions/matching, etc. That makes sense. But is there an
“official
S> workaround” for this problem? And if not, can I rest well at night
with

Yes, correct the problem (i.e. change the permission for the directory)
:slight_smile:

S> my ‘\n’ workaround in my companys stable source tree? It’s just a
S> warning message now, but in the future, I can’t really forsee any

it’s a warning message with $SAFE = 0, but an error with $SAFE >= 1

svg% ruby -e ‘exec(“ls”)’
-e:1: warning: Insecure world writable dir /home/ts/XXX/., mode 040777
svg%

svg% ruby -e ‘$SAFE = 1; exec(“ls”)’
-e:1: warning: Insecure world writable dir /home/ts/XXX/., mode 040777
-e:1:in `exec’: Insecure PATH - ls (SecurityError)
from -e:1
svg%

Guy Decoux

there’s tons of threads about this, e.g.
http://www.ruby-forum.com/topic/191771
Search the mailing list for more

Greetz!

2009/9/1 Hugh H. [email protected]

what is the best gui for ruby and where can i find it?

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