USN-6657-2: Dnsmasq vulnerabilities

24 April 2024

Several security issues were fixed in Dnsmasq.

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Releases

Packages

  • dnsmasq - Small caching DNS proxy and DHCP/TFTP server

Details

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 this issue to
cause Dnsmasq to consume resources, leading to a denial of service.
(CVE-2023-50868)

It was discovered that Dnsmasq incorrectly set the maximum EDNS.0 UDP
packet size as required by DNS Flag Day 2020. This issue only affected
Ubuntu 23.10. (CVE-2023-28450)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.04
Ubuntu 16.04

This update uses a new upstream release, which includes additional bug
fixes. After a standard system update you need to reboot your computer to
make all the necessary changes.