Opened by  (SEKINE Tatsuo) on 2004-06-29 11:01

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510

Description of problem:
/usr/bin/im-switch program use file "/tmp/imswitcher$$" as temporary file.

This way to use temporary file is insecure, because
/tmp/ is everyone writable and $$(PID) is predictable.

When root try to set system-wide setting of IM, attacker can crash
 important file without root privilege.


Version-Release number of selected component (if applicable):
iiimf-x-11.4-46.svn1587

How reproducible:
Always

Steps to Reproduce:
1. an attacker who has onlu normal privilege types as followed:

  $ bash -c 'i=1;while [ $i -lt 65536 ]; do ln -s /etc/IMPORTANT_FILE
/tmp/imswitcher$i; let "i++"; done'

2. root types below to set system-wide IM setting:

  # /usr/bin/im-switch -w -m xim

3.
    

Actual Results:  /etc/IMPORTANT_FILE becomes broken.


Expected Results:  /etc/IMPORTANT_FILE is independent from the
behavior of im-switch program.


Additional info:

mktemp(1) command or "umask 077; mkdir /tmp/..." should be used to
make temporary file(directory).