A Dnsmasq security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, 20.10, and 21.04.
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Ubuntu Security Notice USN-4976-1
June 02, 2021
dnsmasq vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 21.04
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
Summary:
Dnsmasq could be exposed to cache poisoning.
Software Description:
- dnsmasq: Small caching DNS proxy and DHCP/TFTP server
Details:
Petr Mensik discovered that Dnsmasq incorrectly randomized source ports in
certain configurations. A remote attacker could possibly use this issue to
facilitate DNS cache poisoning attacks.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 21.04:
dnsmasq 2.84-1ubuntu2.1
dnsmasq-base 2.84-1ubuntu2.1
dnsmasq-utils 2.84-1ubuntu2.1
Ubuntu 20.10:
dnsmasq 2.82-1ubuntu1.3
dnsmasq-base 2.82-1ubuntu1.3
dnsmasq-utils 2.82-1ubuntu1.3
Ubuntu 20.04 LTS:
dnsmasq 2.80-1.1ubuntu1.4
dnsmasq-base 2.80-1.1ubuntu1.4
dnsmasq-utils 2.80-1.1ubuntu1.4
Ubuntu 18.04 LTS:
dnsmasq 2.79-1ubuntu0.4
dnsmasq-base 2.79-1ubuntu0.4
dnsmasq-utils 2.79-1ubuntu0.4
After a standard system update you need to reboot your computer to make
all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-4976-1
CVE-2021-3448
Package Information:
https://launchpad.net/ubuntu/+source/dnsmasq/2.84-1ubuntu2.1
https://launchpad.net/ubuntu/+source/dnsmasq/2.82-1ubuntu1.3
https://launchpad.net/ubuntu/+source/dnsmasq/2.80-1.1ubuntu1.4
https://launchpad.net/ubuntu/+source/dnsmasq/2.79-1ubuntu0.4
