Products.PloneHotfix20110531 2.0

Important note: This is version 2.0 of the hotfix and fixes a critical issue with version 1.0 of the hotfix. You should update your sites to version 2.0 even if you have already applied version 1.0 of the hotfix. The Plone security team apologizes for this error.

This hotfix fixes the following four vulnerabilities:

1. Reflected XSS attack: A crafted URL can display arbitrary HTML output. This is a vulnerability in CMFPlone affecting all versions of Plone. Thanks to S. Streichsbier of SEC Consult for the responsible disclosure. See CVE-2011-1948 for details.

2. Persistent XSS attack: Certain valid HTML will allow Javascript filtering to be bypassed. This is a vulnerability in Products.PortalTransforms affecting all versions of Plone using it, including 2.1 through 4.1. Thanks to Daniel Berlin and Dan Bentley both of Google and Brian Peters an independent researcher, for responsibly disclosing this independently of each other. See CVE-2011-1949 for details.

3. Unauthorized data changes: One form allows users to edit the properties of other users. This is a vulnerability in plone.app.users affecting Plone 4.0 and 4.1. This vulnerability was not disclosed responsibly to the security team. See CVE-2011-1950 for details.

4. Denial of service: A user can prevent other users from logging in. This is a vulnerability in Products.PluggableAuthService affecting all versions of Plone using it, including 2.5 through 4.1. Thanks to Alan Hoey of Team Rubber for the responsible disclosure. See PAS ticket #789858 for details.

This hotfix is supported on Plone 3 and 4. It is also known to work on Plone 2.5, and may work on older versions of Plone.

The fixes included here will be incorporated into subsequent releases of Plone, so Plone 4.0.7, 4.1rc3, and greater should not require this hotfix.