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Ubuntu Security Notice USN-6657-1
February 26, 2024
dnsmasq vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 23.10
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in Dnsmasq.
Software Description:
- dnsmasq: Small caching DNS proxy and DHCP/TFTP server
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:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 23.10:
   dnsmasq-base                    2.90-0ubuntu0.23.10.1
Ubuntu 22.04 LTS:
   dnsmasq-base                    2.90-0ubuntu0.22.04.1
Ubuntu 20.04 LTS:
   dnsmasq-base                    2.90-0ubuntu0.20.04.1
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.
References:
   https://ubuntu.com/security/notices/USN-6657-1
   CVE-2023-28450, CVE-2023-50387, CVE-2023-50868
Package Information:
   https://launchpad.net/ubuntu/+source/dnsmasq/2.90-0ubuntu0.23.10.1
   https://launchpad.net/ubuntu/+source/dnsmasq/2.90-0ubuntu0.22.04.1
   https://launchpad.net/ubuntu/+source/dnsmasq/2.90-0ubuntu0.20.04.1