USN-6657-2: Dnsmasq vulnerabilities

USN-6657-1 fixed several vulnerabilities in Dnsmasq. This update provides
the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.

Original advisory details:

Elias Heftrig, Haya Schulmann, Niklas Vogel, and Michael Waidner discovered
that Dnsmasq icorrectly handled validating DNSSEC messages. A remote
attacker could possibly use this issue to cause Dnsmasq to consume
resources, leading to a denial of service. (CVE-2023-50387)

It was discovered that Dnsmasq incorrectly handled preparing an NSEC3
closest encloser proof. A remote attacker could possibly use …

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