Portage is the default Gentoo package management system.
Mike Frysinger reported that the "etc-update" utility uses temporary files with the standard umask, which results in the files being world-readable when merging configuration files in a default setup.
A local attacker could access sensitive information when configuration files are being merged.
There is no known workaround at this time.
All Portage users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=sys-apps/portage-184.108.40.206"