Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Thu, 27 Oct 2016 16:24:35 -0600
From: Kurt Seifried <kseifried@...hat.com>
To: oss-security <oss-security@...ts.openwall.com>
Cc: openstack@...ts.openstack.org, openstack-dev@...ts.openstack.org
Subject: Re: [OSSN-0076] Glance Image service v1 and v2 api
 image-create vulnerability

Just a note this was assigned CVE-2016-8611

On Thu, Oct 27, 2016 at 3:42 PM, Luke Hinds <lhinds@...hat.com> wrote:

> Glance Image service v1 and v2 api image-create vulnerability
> ---
>
> ### Summary ###
> No limits are enforced within the Glance image service for both v1 and
> v2 `/images` API POST method for authenticated users, resulting in
> possible denial of service attacks through database table saturation.
>
> ### Affected Services / Software ###
> All versions of Glance image service.
>
> ### Discussion ###
> Within the Glance image service, calls to the POST method within v1 or
> v2/images creates an image (record) in `queued` status. There is no
> limit enforced within the Glance API on the number of images a single
> tenant may create, just on the total amount of storage a single user may
> consume.
>
> Therefore a user could either maliciously or unintentionally fill
> multiple database tables (images, image_properties, image_tags,
> image_members) with useless image records, thereby causing a denial of
> service by lengthening transaction response times in the Glance database.
>
> ### Recommended Actions ###
> For all versions of Glance that expose either the v1 and v2/images API,
> operators are recommended to deploy external rate-limiting proxies or
> web application firewalls, to provide a front layer of protection to
> glance. The Glance database should be monitored for abnormal growth.
> Although rate-limiting does not eliminate this attack vector, it will
> slow it to the point where you can react prior to a denial of service
> occurring.
>
> The following solutions may be considered, however it is key that the
> operator carefully plans and considers the individual performance needs
> of users and services within their OpenStack cloud, when configuring any
> rate limiting functionality.
>
> #### Repose ####
> Repose provides a rate limiting filter, that can utilise limits by IP,
> Role (OpenStack Identity v3 filter) or header.
>
> https://repose.atlassian.net/wiki/display/REPOSE/Rate+Limiting+Filter
>
> #### NGINX ####
> NGINX provides the limit_req_module, which can be used to provide a
> global rate
> limit. By means of a `map`, it can be limited to just the POST method.
>
> Further details can be found on the nginx site:
> http://nginx.org/en/docs/http/ngx_http_limit_req_module.html
>
> #### HAProxy ####
> HAProxy can provide inherent rate-limiting using stick-tables with a
> General
> Purpose Counter (gpc)
>
> Further details can be found on the haproxy website:
>
> http://blog.haproxy.com/2012/02/27/use-a-load-balancer-as-
> a-first-row-of-defense-against-ddos
>
> #### Apache ####
> A number of solutions can be explored here as follows.
>
> ##### mod_ratelimit #####
> http://httpd.apache.org/docs/2.4/mod/mod_ratelimit.html
>
> ##### mod_qos #####
> http://opensource.adnovum.ch/mod_qos/dos.html
>
> ##### mod_evasive #####
> https://www.digitalocean.com/community/tutorials/how-to-
> protect-against-dos-and-ddos-with-mod_evasive-for-apache-on-centos-7
>
> ##### mod_security #####
> https://www.modsecurity.org/
>
> #### Limit `add_image` to admin role ####
>
> Another possible mitigation is to restrict image creation to the admin
> role, however this should only be done for those cases in which there
> are Glance nodes dedicated to end-user access only. Restriction to admin
> only on Glance nodes that serve OpenStack services will for example,
> remove the ability to create snapshots from the Compute API or to create
> bootable volumes from Cinder.
>
> To restrict image creation to the role admin only, amend
> `/etc/glance/policy.json` accordingly.
>
>     "add_image": "role:admin",
>
> ### Contacts / References ###
> Author: Luke Hinds, Red Hat
> This OSSN : https://wiki.openstack.org/wiki/OSSN/OSSN-0076
> Original LaunchPad Bug : https://bugs.launchpad.net/ossn/+bug/1545092
> OpenStack Security ML : openstack-security@...ts.openstack.org
> OpenStack Security Group : https://launchpad.net/~openstack-ossg
>
>
>


-- 

--
Kurt Seifried -- Red Hat -- Product Security -- Cloud
PGP A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
Red Hat Product Security contact: secalert@...hat.com

Powered by blists - more mailing lists

Your e-mail address:

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.