[Zope3-Users] Security alert: use of Through-the-Web
jim at zope.com
Sat Jul 8 08:43:00 EDT 2006
Recently, a serious security flaw was found in Zope 2 due to it's
improper support for allowing reStructuredText to be edited through-
the-web. reStructuredText has directives that allow inclusion of any
file a Zope process could read and inclusion of data obtained from
fetching arbitrary URLs. In a trusted environment, these directives
have legitimate uses. The feature of including files and URL results
should not be enabled for text entered from untrusted sources, which
applies to most through-the-web interactions.
The recent hotfix:
addresses the problem for Zope 2.
It is safe to allow reStructuredText through the web with care. The
inclusion of files or URL results can be disabled, but the programmer
must explicitly disable the feature. It is not disabled by default.
It is also critical that a developer who exposes through-the-web
reStructuredText have tests to verify that the file/url inclusion
feature has been disabled.
Zope 3 itself, as released, doesn't have this problem because it
doesn't allow reST entry through the web. There are third-party
applications, however, including 2 packages in the Zope 3 subversion
tree that do have this problem. I strongly urge you to avoid using
any Zope package that allows through-the-web input of
reStructuredText unless you can verify that file/url has been
The zwiki and bugtracker packages do not currently disable file/url
inclusion and should not be used in situations in which users who are
not highly trusted have access to these applications. If you are
using a Zope 3 checkout, these packages are currently included and
enabled. I plan to remove these packages from the Zope 3 repository
tree within the next few hours. If you are using a checkout-based
Zope 3 installation that exposes these packages to untrusted users,
you are strongly urged to disable these packages by removing the
following files from your package-includes directory:
Removing these files will also avoid problems when you update your
checkout later, as these will refer to non-existent packages.
Jim Fulton mailto:jim at zope.com Python Powered!
CTO (540) 361-1714 http://www.python.org
Zope Corporation http://www.zope.com http://www.zope.org
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