The __netlink_deliver_tap_skb function in net/netlink/af_netlink.c in the Linux kernel through 4.14.4, when CONFIG_NLMON is enabled, does not restrict observations of Netlink messages to a single net namespace, which allows local users to obtain sensitive information by leveraging the CAP_NET_ADMIN capability to sniff an nlmon interface for all Netlink activity on the system. https://nvd.nist.gov/vuln/detail/CVE-2017-17449
