XSS and sandbox escape vulnerability

Available downloads


MD5: 760c82c6394a9a7b5645b99d607e0beb
SHA1: 4c77b929eaa6494418c4284455e2c46406bd1368
For all platforms (7010 bytes)

Plone affected versions

  • 5.1a2
  • 5.1a1
  • 5.0.6
  • 5.0.5
  • 5.0.4
  • 5.0.3
  • 5.0.2
  • 5.0.1
  • 5.0
  • 5.0rc3
  • 5.0rc2
  • 5.0rc1
  • 4.3.11
  • 4.3.10
  • 4.3.9
  • 4.3.8
  • 4.3.7
  • 4.3.6
  • 4.3.5
  • 4.3.4
  • 4.3.3
  • 4.3.2
  • 4.3.1
  • 4.3
  • 4.2.7
  • 4.2.6
  • 4.2.5
  • 4.2.4
  • 4.2.3
  • 4.2.2
  • 4.2.1
  • 4.2
  • 4.1.6
  • 4.1.5
  • 4.1.4
  • 4.1.3
  • 4.1.2
  • 4.1.1
  • 4.1
  • 4.0.10
  • 4.0.9
  • 4.0.8
  • 4.0.7
  • 4.0.5
  • 4.0.4
  • 4.0.3
  • 4.0.2
  • 4.0.1
  • 4.0
  • 3.3.6
  • 3.3.5
  • 3.3.4
  • 3.3.3
  • 3.3.2
  • 3.3.1
  • 3.3
  • 2.5.5

Release Notes

CVE numbers: CVE-2016-7147 and one not yet issued.

Versions Affected: All supported Plone versions (4.3.11 and any earlier 4.x version, 5.0.6 and any earlier 5.x version). Previous versions could be affected but have not been fully tested.

Versions Not Affected: None.

Nature of vulnerability: the patch will address a reflected XSS vulnerability in Zope and a partial sandbox escape vulnerability available to system administrators.

Version support: The hotfix is officially supported by the Plone security team on the following versions of Plone in accordance with the Plone version support policy: 4.0.10, 4.1.6, 4.2.7, 4.3.11 and 5.0.6. However, it has also received some testing on older versions of Plone.

The fixes included here will be incorporated into subsequent releases of Plone, so Plone 4.3.12, 5.0.7 and greater should not require this hotfix. 

Credit: Thanks to Tim Coen of Curesec GmbH for the responsible disclosure of the XSS vulnerability. The partial sandbox escape was found by the Plone security team, inspired by Armin Ronacher's writings on the subject.

Installation instructions

The procedure for installing Hotfix 20170117 differs slightly based on which version of Plone or Zope you are running, and whether you installed Plone or Zope using buildout.

Backup First!

It is prudent to backup all your data and installation files before installing any Plone add-on, including this hotfix.  If you already have a solid Plone backup routine in place, then you can skip this step and proceed.

If you don't already have a backup of your Plone site, the simplest way to back up your Plone instance is to simply copy your entire Zope instance folder or buildout folder to a secure location.

Recommended Install Procedure

If you're less experienced with Plone, the easiest way to install Hotfix 20170117 on Plone 4.0 - Plone 5.x is as follows:

1) Download the hotfix archive using the link above.  If you have an md5 tool available (Linux or Mac), use it to check that the signature matches.

2) Place the downloaded zip file into the "products" directory in your Zope instance. On pre-buildout installations, this will be "Products".

3) Unpack the zip file.

On Linux or Mac, the command is:

 $ unzip PloneHotfix20170117-1.0.zip

On Windows, use your favorite archiving product. (7Zip is a good choice).

4)  Restart your Zope instance in foreground mode to ensure that the hotfix is installed.

On Mac or Linux, the command is typically:

 $ bin/instance fg

On Windows, the command is typically:

> bin\instance.exe fg

Zope will start in the foreground, and you should see the message "INFO PloneHotfix20170117 Hotfix installed." during startup.

5) Stop the foreground instance of Zope by hitting CTRL-C

6) Restart your Zope instance.

On Mac or Linux, the command is typically:

$ bin/instance start

On Windows, the command is typically:

> bin\instance.exe start

If you're using ZEO clients, change instance to client1, client2, etc., in the above commands.


Installing with Buildout

If you are an experienced Plone administrator, and you are using a buildout-based installation of Plone, you may choose to install Hotfix 20170117 with buildout. However, if you choose to do this, you must be certain that you will not accidentally overwrite Plone components with newer versions.  This is particularly likely if you try to use buildout with older versions of Plone.

If you are not sure what you're doing, please use the "Recommended Installation Instructions" above.

1) Find your buildout.cfg file, typically located in the "zinstance" subdirectory of your Plone installation directory. (If you're using ZEO clients, the subdirectory may be called "zeoserver").

2) Open your buildout.cfg file in your text editor. 

3) Scroll down to the "eggs" section of the buildout and add Products.PloneHotfix20170117, e.g.

eggs = 

Products.PloneHotfix20170117 = 1.0

4) Rerun buildout.

On Mac or Linux, the command is:

$ ./bin/buildout -Nv

On windows, the command is:

> bin\buildout.exe -Nv

5) Restart your Zope instance.

On Mac or Linux, the command is:

$ ./bin/instance start

On Windows, the command is:

> bin\instance.exe start

Alternatively, on Windows, you may restart the Zope service via the Windows Services control panel.

If you're using ZEO clients, change instance to client1, client2, etc., in the above commands.

Installation continued

On startup, the hotfix will log a number of messages to the Zope event log. You can use this to confirm the patch is successfully installed. They look like this:

2017-01-17 05:24:44 INFO Products.PloneHotfix20170117 Applied zmi patch
2017-01-17 05:24:44 INFO Products.PloneHotfix20170117 Applied strformat patch
2017-01-17 05:24:44 INFO Products.PloneHotfix20170117 Hotfix installed


Issues fixed