Several security issues were fixed in ldns.
Leon Weber discovered that the ldns-keygen tool incorrectly set permissions on private keys. A local attacker could possibly use this issue to obtain generated private keys. This issue only applied to Ubuntu 14.04 LTS. (CVE-2014-3209)
22 November 2017
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in ldns.
Leon Weber discovered that the ldns-keygen tool incorrectly set permissions on private keys. A local attacker could possibly use this issue to obtain generated private keys. This issue only applied to Ubuntu 14.04 LTS. (CVE-2014-3209)
Stephan Zeisberg discovered that ldns incorrectly handled memory when processing data. A remote attacker could use this issue to cause ldns to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2017-1000231, CVE-2017-1000232)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.