Bruce Momjian writes:
> This brings up a question. If I have pid 333 and someone creates a file
> world-writable called /tmp/333, and I go and do:
> cat file >/tmp/$$
> isn't another user now able to modify those temp file contents. Is that
> the insecurity you mentioned Peter, and if so, how do you prevent this?
That is one possibility. Another exploit is with a symlink from /tmp/333
to a file you want to overwrite. This is more fun with root, but it's
still not a good idea here.
To securely create a temp file in shell you need to use mktemp(1), or do
something like (umask 077 && mkdir $TMPDIR/$$) to create a subdirectory.
Needless to say, it's tricky.
Peter Eisentraut peter_e(at)gmx(dot)net http://funkturm.homeip.net/~peter
In response to
pgsql-hackers by date
|Next:||From: Peter Eisentraut||Date: 2001-06-24 11:28:00|
|Subject: Re: Setuid functions|
|Previous:||From: Larry Rosenman||Date: 2001-06-24 11:05:29|
|Subject: Re: Why would this use 600Meg of VM?|
pgsql-committers by date
|Next:||From: Bruce Momjian||Date: 2001-06-24 21:18:34|
|Subject: Re: [COMMITTERS] pgsql/src/bin/initdb initdb.sh|
|Previous:||From: Bruce Momjian - CVS||Date: 2001-06-24 02:41:21|
|Subject: pgsql/src backend/parser/parse_coerce.c backen ...|