Ubuntu Security Notice 4294-1 - 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. 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.
5b6805dc7503709eaa6444271d78fe6c8eb7dcb5aa91a23ed44fee1b7b1d5835