Tatsuya Kinoshita discovered that IM, which contains interface commands and Perl libraries for E-mail and NetNews, creates temporary files insecurely.
- The impwagent program creates a temporary directory in an insecure manner in /tmp using predictable directory names without checking the return code of mkdir, so it's possible to seize a permission of the temporary directory by local access as another user.
- The immknmz program creates a temporary file in an insecure manner in /tmp using a predictable filename, so an attacker with local access can easily create and overwrite files as another user.
These problems have been fixed in version 141-18.1 for the current stable distribution (woody), in version 133-2.2 of the old stable distribution (potato) and in version 141-20 for the unstable distribution (sid).
We recommend that you upgrade your IM package.