The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files.
CVSS 3.1HIGH 7.0·Local·Low privileges·No interaction·EPSS 0.00373·Published 2018-08-21·Fixed in 10.1ubuntu2.2CWE-59