Perl is a stable, cross-platform programming language created by Larry Wall.
Some Perl modules create temporary files in world-writable directories with predictable names.
A local attacker could create symbolic links in the temporary files directory, pointing to a valid file somewhere on the filesystem. When a Perl script is executed, this would result in the file being overwritten with the rights of the user running the utility, which could be the root user.
There is no known workaround at this time.
All Perl users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=perl-5.8.5-r2"