USN-5332-1 fixed a vulnerability in Bind. This update provides the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
Original advisory details:
Xiang Li, Baojun Liu, Chaoyi Lu, and Changgen Zou discovered that Bind incorrectly handled certain bogus NS records when using forwarders. A remote attacker could possibly use this issue to manipulate cache results. (CVE-2021-25220)
{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "bind9",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "bind9-host",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "bind9utils",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "dnsutils",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "host",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "libbind-dev",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "libbind9-90",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "libdns100",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "libisc95",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "libisccc90",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "libisccfg90",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "liblwres90",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        },
        {
            "binary_name": "lwresd",
            "binary_version": "1:9.9.5.dfsg-3ubuntu0.19+esm6"
        }
    ]
}
          {
    "cves": [
        {
            "id": "CVE-2021-25220",
            "severity": [
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N"
                },
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N"
                },
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:Pro:14.04:LTS"
}
                {
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "bind9",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "bind9-host",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "bind9utils",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "dnsutils",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "host",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libbind-dev",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libbind-export-dev",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libbind9-140",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libdns-export162",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libdns162",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libirs-export141",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libirs141",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libisc-export160",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libisc160",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libisccc-export140",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libisccc140",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libisccfg-export140",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "libisccfg140",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "liblwres141",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        },
        {
            "binary_name": "lwresd",
            "binary_version": "1:9.10.3.dfsg.P4-8ubuntu1.19+esm2"
        }
    ]
}
          {
    "cves": [
        {
            "id": "CVE-2021-25220",
            "severity": [
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N"
                },
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N"
                },
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:Pro:16.04:LTS"
}