USN-6657-2: Dnsmasq vulnerabilities

Publication date

24 April 2024

Overview

Several security issues were fixed in Dnsmasq.


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. (

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)


Update instructions

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.

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
18.04 bionic dnsmasq-base –  2.90-0ubuntu0.18.04.1+esm1  
16.04 xenial dnsmasq-base –  2.90-0ubuntu0.16.04.1+esm1  

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