sudo (su “do”) allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments.
The fix present in app-admin/sudo-1.8.20_p1 (GLSA 201705-15) was incomplete as it did not address the problem of a command with a newline in the name.
A local attacker could execute arbitrary code with root privileges.
There is no known workaround at this time.
All sudo users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-admin/sudo-1.8.20_p2"