Several security issues were fixed in opensmtpd.
It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could use this vulnerability to execute arbitrary shell commands as any non-root user. (CVE-2020-8794)
2 March 2020
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in opensmtpd.
It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could use this vulnerability to execute arbitrary shell commands as any non-root user. (CVE-2020-8794)
It was discovered that OpenSMTPD did not properly handle hardlinks under certain conditions. An unprivileged local attacker could read the first line of any file on the filesystem. (CVE-2020-8793)
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.