zlib is a general-purpose data-compression library.
zlib contains a bug in the handling of errors in the "inflate()" and "inflateBack()" functions.
An attacker could exploit this vulnerability to launch a Denial of Service attack on any application using the zlib library.
There is no known workaround at this time. All users are encouraged to upgrade to the latest available version of zlib.
All zlib users should upgrade to the latest version:
# emerge sync
# emerge -pv ">=sys-libs/zlib-1.2.1-r3"
# emerge ">=sys-libs/zlib-1.2.1-r3"
You should also run revdep-rebuild to rebuild any packages that depend on older versions of zlib :
# revdep-rebuild