A vulnerability was discovered and corrected in dovecot:
Dovecot 1.2.x before 1.2.8 sets 0777 permissions during creation of
certain directories at installation time, which allows local users to
access arbitrary user accounts by replacing the auth socket, related
to the parent directories of the base_dir directory, and possibly
the base_dir directory itself (CVE-2009-3897).
The updated packages have been patched to correct these issues.