Synopsis
The remote Ubuntu host is missing one or more security-related patches.
Description
Ben Hawkes discovered an integer overflow in the Linux netfilter implementation. On systems running 32 bit kernels, a local unprivileged attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2016-3135)
It was discovered that the keyring implementation in the Linux kernel did not ensure a data structure was initialized before referencing it after an error condition occurred. A local attacker could use this to cause a denial of service (system crash). (CVE-2016-4470)
Sasha Levin discovered that a use-after-free existed in the percpu allocator in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2016-4794)
Kangjie Lu discovered an information leak in the netlink implementation of the Linux kernel. A local attacker could use this to obtain sensitive information from kernel memory. (CVE-2016-5243).
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
Solution
Update the affected linux-image-4.4-generic, linux-image-4.4-generic-lpae and / or linux-image-4.4-lowlatency packages.