tempfile.mktemp() and symlink attacks

[Neil Schemenauer]

Aahz wrote:
> [I'm reposting this because nobody followed up to it.  I tried doing
> some research because I know there have been changed for Python 2.3, but
> I wasn't able to find the relevant posts on python-dev.]
> 
> In article <3ygu9.105734$La5.330766 at rwcrnsc52.ops.asp.att.net>,
> Kent Hu  <kenthu at kenNOSPAMthu.net> wrote:
> >Is using tempfile.mktemp() vulnerable to symlink attacks?

Yes.  mktemp() just gives you a name.  Someone nasty could create a
symlink with that name before you.  You should open the file using:

    os.open(name, os.O_RDWR|os.O_CREAT|os.O_EXCL, 0700)

tempfile.TemporaryFile already does this.  2.3 has a handy function
called mkstemp that returns a name and an open file descriptor. 

HTH,

  Neil