USN-4397-1

It was discovered that NSS incorrectly handled the TLS State Machine. A remote attacker could possibly use this issue to cause NSS to hang, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 19.10. (CVE-2019-17023)

Cesar Pereida Garcia discovered that NSS incorrectly handled DSA key generation. A local attacker could possibly use this issue to perform a timing attack and recover DSA keys. (CVE-2020-12399)