mount.cifs in cifs-utils 2.6 allows local users to determine the existence of arbitrary files or directories via the file path in the second argument, which reveals their existence in an error message.
{ "availability": "No subscription required", "binaries": [ { "binary_name": "cifs-utils", "binary_version": "2:6.4-1ubuntu1.1" }, { "binary_name": "cifs-utils-dbgsym", "binary_version": "2:6.4-1ubuntu1.1" } ] }