gdm3 versions before 3.36.2 or 3.38.2 would start gnome-initial-setup if gdm3 can't contact the accountservice service via dbus in a timely manner; on Ubuntu (and potentially derivatives) this could be be chained with an additional issue that could allow a local user to create a new privileged account.
{ "binaries": [ { "binary_name": "gdm3", "binary_version": "3.28.3-0ubuntu18.04.6" }, { "binary_name": "gdm3-dbgsym", "binary_version": "3.28.3-0ubuntu18.04.6" }, { "binary_name": "gir1.2-gdm-1.0", "binary_version": "3.28.3-0ubuntu18.04.6" }, { "binary_name": "libgdm-dev", "binary_version": "3.28.3-0ubuntu18.04.6" }, { "binary_name": "libgdm1", "binary_version": "3.28.3-0ubuntu18.04.6" }, { "binary_name": "libgdm1-dbgsym", "binary_version": "3.28.3-0ubuntu18.04.6" } ], "ubuntu_priority": "medium", "availability": "No subscription required" }
{ "binaries": [ { "binary_name": "gdm3", "binary_version": "3.36.3-0ubuntu0.20.04.2" }, { "binary_name": "gdm3-dbgsym", "binary_version": "3.36.3-0ubuntu0.20.04.2" }, { "binary_name": "gir1.2-gdm-1.0", "binary_version": "3.36.3-0ubuntu0.20.04.2" }, { "binary_name": "libgdm-dev", "binary_version": "3.36.3-0ubuntu0.20.04.2" }, { "binary_name": "libgdm1", "binary_version": "3.36.3-0ubuntu0.20.04.2" }, { "binary_name": "libgdm1-dbgsym", "binary_version": "3.36.3-0ubuntu0.20.04.2" } ], "ubuntu_priority": "medium", "availability": "No subscription required" }