GNU cpio copies files into or out of a cpio or tar archive.
A buffer overflow vulnerability in the safer_name_suffix() function in GNU cpio has been discovered.
A remote attacker could entice a user to open a specially crafted archive file resulting in a stack-based buffer overflow, possibly crashing the application. It is disputed whether the execution of arbitrary code is possible.
There is no known workaround at this time.
All GNU cpio users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-arch/cpio-2.9-r1"