Documentation: instance image temp url and configdrive can be obtained via unauthorized API endpoint

[Yuriy Zveryanskyy]

For any node instance temp url and configdrive can be obtained if:
1) The node in DEPLOYWAIT state
2) Person has network access to ironic API (without authorization)
3) Conductor is able to send request to host that is controlled by person above

Obtaining data:
1) Prepare and run simple IPA API simulator on host
2) Send fake heartbeat with address of the host above to ironic API
3) Conductor send prepare image command with data to the host

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/466729

[OpenStack Infra (hudson-openstack)]

Change abandoned by Yuriy Zveryanskyy (<email address hidden>) on branch: master
Review: https://review.openstack.org/466729

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/466729
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=d81d2e7736cde319e5cb9ff8db334df1af264d84
Submitter: Zuul
Branch: master

commit d81d2e7736cde319e5cb9ff8db334df1af264d84
Author: Yuriy Zveryanskyy <email address hidden>
Date: Mon May 22 16:14:53 2017 +0300

    Add 'Other considerations' to security doc

    This adds an 'Other considerations' section to the Security
    documentation to include things that may not merit their
    own section.

    Change-Id: Ic4a854a9fb8e12e0d6cdf969ef804e25f6341a32
    Related-bug: #1659455
    Related-bug: #1692511
    Co-Authored-By: Ruby Loo <email address hidden>