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.
- https://usn.ubuntu.com/3583-2/
- https://github.com/ARPSyndicate/cvemon