=========================================================================Ubuntu Security Notice USN-5658-1
October 05, 2022

isc-dhcp vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in DHCP.

Software Description:
- isc-dhcp: DHCP server and client

Details:

It was discovered that DHCP incorrectly handled option reference counting.
A remote attacker could possibly use this issue to cause DHCP servers to
crash, resulting in a denial of service. (CVE-2022-2928)

It was discovered that DHCP incorrectly handled certain memory operations.
A remote attacker could possibly use this issue to cause DHCP clients and
servers to consume resources, leading to a denial of service.
(CVE-2022-2929)

Update instructions:

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

Ubuntu 22.04 LTS:
  isc-dhcp-client                 4.4.1-2.3ubuntu2.3
  isc-dhcp-server                 4.4.1-2.3ubuntu2.3

Ubuntu 20.04 LTS:
  isc-dhcp-client                 4.4.1-2.1ubuntu5.20.04.4
  isc-dhcp-server                 4.4.1-2.1ubuntu5.20.04.4

Ubuntu 18.04 LTS:
  isc-dhcp-client                 4.3.5-3ubuntu7.4
  isc-dhcp-server                 4.3.5-3ubuntu7.4

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5658-1
  CVE-2022-2928, CVE-2022-2929

Package Information:
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.4.1-2.3ubuntu2.3
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.4.1-2.1ubuntu5.20.04.4
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.3.5-3ubuntu7.4