CVE-2017-7493 Qemu: 9pfs: guest privilege escalation in virtfs mapped-file mode

[P J P <ppandit () redhat com>]

  Hello,

Quick Emulator(Qemu) built with the VirtFS, host directory sharing via Plan 9 
File System(9pfs) support, is vulnerable to an improper access control issue. 
It could occur while accessing virtfs metadata files in mapped-file security 
mode.

A guest user could use this flaw to escalate their privileges inside guest.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg03663.html

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1451709

'CVE-2017-7493' has been assigned to this issue by Red Hat Inc.

It was reported by Leo Gaspard.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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