USN-4967-1 fixed a vulnerability in nginx. This update provides the corresponding update for Ubuntu 14.04 ESM and 16.04 ESM.
Original advisory details:
Luis Merino, Markus Vervier, and Eric Sesterhenn discovered that nginx incorrectly handled responses to the DNS resolver. A remote attacker could use this issue to cause nginx to crash, resulting in a denial of service, or possibly execute arbitrary code.
{
    "binaries": [
        {
            "binary_name": "nginx",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-common",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-core",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-extras",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-full",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-light",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-naxsi",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        },
        {
            "binary_name": "nginx-naxsi-ui",
            "binary_version": "1.4.6-1ubuntu3.9+esm2"
        }
    ],
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
          {
    "binaries": [
        {
            "binary_name": "nginx",
            "binary_version": "1.10.3-0ubuntu0.16.04.5+esm1"
        },
        {
            "binary_name": "nginx-common",
            "binary_version": "1.10.3-0ubuntu0.16.04.5+esm1"
        },
        {
            "binary_name": "nginx-core",
            "binary_version": "1.10.3-0ubuntu0.16.04.5+esm1"
        },
        {
            "binary_name": "nginx-extras",
            "binary_version": "1.10.3-0ubuntu0.16.04.5+esm1"
        },
        {
            "binary_name": "nginx-full",
            "binary_version": "1.10.3-0ubuntu0.16.04.5+esm1"
        },
        {
            "binary_name": "nginx-light",
            "binary_version": "1.10.3-0ubuntu0.16.04.5+esm1"
        }
    ],
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}