CVE 2021-3155

snapd 2.54.2 and earlier created ~/snap directories in user home directories without specifying owner-only permissions. This could allow a local attacker to read information that should have been private. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

See the CVE page on Mitre.org for more details.