Ubuntu 20.04 LTS USN-4698-2 Critical DoS: Dnsmasq Regresions Fix

ubuntu

February 24, 2021

USN-4698-1 introduced regressions in Dnsmasq.

Summary

USN-4698-1 introduced regressions in Dnsmasq.

Software Description:

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

Details:

USN-4698-1 fixed vulnerabilities in Dnsmasq. The updates introduced

regressions in certain environments related to issues with multiple

queries, and issues with retries. This update fixes the problem.

Original advisory details:

Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled

memory when sorting RRsets. A remote attacker could use this issue to cause

Dnsmasq to hang, resulting in a denial of service, or possibly execute

arbitrary code. (CVE-2020-25681, CVE-2020-25687)

Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled

extracting certain names. A remote attacker could use this issue to cause

Dnsmasq to hang, resulting in a denial of service, or possibly execute

arbitrary code. (CVE-2020-25682, CVE-2020-25683)

Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrec...

Read the Full Advisory

Topics Covered

security advisory denial of service update critical Ubuntu ubuntu regression dnsmasq

Update Instructions

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

Ubuntu 20.10:
  dnsmasq                         2.82-1ubuntu1.2
  dnsmasq-base                    2.82-1ubuntu1.2
  dnsmasq-utils                   2.82-1ubuntu1.2

Ubuntu 20.04 LTS:
  dnsmasq                         2.80-1.1ubuntu1.3
  dnsmasq-base                    2.80-1.1ubuntu1.3
  dnsmasq-utils                   2.80-1.1ubuntu1.3

Ubuntu 18.04 LTS:
  dnsmasq                         2.79-1ubuntu0.3
  dnsmasq-base                    2.79-1ubuntu0.3
  dnsmasq-utils                   2.79-1ubuntu0.3

Ubuntu 16.04 LTS:
  dnsmasq                         2.75-1ubuntu0.16.04.8
  dnsmasq-base                    2.75-1ubuntu0.16.04.8
  dnsmasq-utils                   2.75-1ubuntu0.16.04.8

After a standard system update you need to reboot your computer to make
all the necessary changes.