CVE 2018-6559
The Linux kernel, as used in Ubuntu 18.04 LTS and Ubuntu 18.10, allows local users to obtain names of files in which they would not normally be able to access via an overlayfs mount inside of a user namespace.
Related bugs and status
CVE-2018-6559 (Candidate) is related to these bugs:
Bug #1801878: NULL pointer dereference at 0000000000000020 when access dst_orig->ops->family in function xfrm_lookup_with_ifid()
Bug #1799794: [Bionic][Cosmic] Fix to ipmi to support vendor specific messages greater than 255 bytes
Bug #1801924: CVE-2018-18955: nested user namespaces with more than five extents incorrectly grant privileges over inode
See the
CVE page on Mitre.org
for more details.