The Network UPS Tools (NUT) provide support for power devices.
An error in the addchar() function in parseconf.c may cause a buffer overflow.
A remote attacker could send a specially crafted string to upsd, possibly resulting in execution of arbitrary code with the privileges of the process or a Denial of Service condition.
There is no known workaround at this time.
All NUT users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-power/nut-2.6.3"