CVE-2016-4998 on Ubuntu 16.04 LTS (xenial) - medium.
Description:
The IPT_SO_SET_REPLACE setsockopt implementation in the netfilter subsystem in the Linux kernel before 4.6 allows local users to cause a denial of service (out-of-bounds read) or possibly obtain sensitive information from kernel heap memory by leveraging in-container root access to provide a crafted offset value that leads to crossing a ruleset blob boundary. Jesse Hertz and Tim Newsham discovered that the Linux netfilter implementation did not correctly perform validation when handling IPT_SO_SET_REPLACE events. A local unprivileged attacker could use this to cause a denial of service (system crash) or obtain potentially sensitive information from kernel memory.