Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service, unauthorised information disclosure or unauthorised information modification. CVE-2015-2925 Jann Horn discovered that when a subdirectory of a filesystem was bind-mounted into a chroot or mount namespace, a user that should be confined to that chroot or namespace could access the whole of that filesystem if they had write permission on an ancestor of the subdirectory. This is not a common configuration for wheezy, and the issue has previously been fixed for jessie. CVE-2015-5257 Moein Ghasemzadeh of Istuary Innovation Labs reported that a USB device could cause a denial of service by imitating a Whiteheat USB serial device but presenting a smaller number of endpoints. CVE-2015-5283 Marcelo Ricardo Leitner discovered that creating multiple SCTP sockets at the same time could cause a denial of service if the sctp module had not previously been loaded. This issue only affects jessie. CVE-2015-7613 Dmitry Vyukov discovered that System V IPC objects were made accessible before their ownership and other attributes were fully initialised. If a local user can race against another user or service creating a new IPC object, this may result in unauthorised information disclosure, unauthorised information modification, denial of service and/or privilege escalation. A similar issue existed with System V semaphore arrays, but was less severe because they were always cleared before being fully initialised.