Ubuntu has reported today, then has multiple vulnerability. The remote Ubuntu host is missing a security-related patches.
Version of Ubuntu 16.04 LTS / 18.04 LTS / 20.04: is vulnerable on NSS (USN-4478-1).
It was discovered that NSS incorrectly handled some inputs. An attacker could possibly use this issue to expose sensitive information.
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
Update the affected libnss3 package is the solution.
For more details you can see in this link .