CVE-2019-11328: Improper Access Control

An issue was discovered in Singularity, a malicious user with local/network access to the host system (e.g. ssh) could exploit this vulnerability due to insecure permissions allowing a user to edit files within /run/singularity/instances/sing/<user>/<instance>. The manipulation of those files can change the behavior of the starter-suid program when instances are joined resulting in potential privilege escalation on the host.