net/netfilter/xt_osf.c in the Linux kernel through 4.14.4 does not require the CAP_NET_ADMIN capability for add_callback and remove_callback operations, which allows local users to bypass intended access restrictions because the xt_osf_fingers data structure is shared across all net namespaces.
lists.opensuse.org/opensuse-security-announce/2018-01/msg00007.html
www.securityfocus.com/bid/102110
lkml.org/lkml/2017/12/5/982
usn.ubuntu.com/3583-1/
usn.ubuntu.com/3583-2/
usn.ubuntu.com/3617-1/
usn.ubuntu.com/3617-2/
usn.ubuntu.com/3617-3/
usn.ubuntu.com/3619-1/
usn.ubuntu.com/3619-2/
usn.ubuntu.com/3632-1/
www.debian.org/security/2017/dsa-4073
www.debian.org/security/2018/dsa-4082