-Let's do an ikiwiki security analysis.
-
If you are using ikiwiki to render pages that only you can edit, do not
generate any wrappers, and do not use the cgi, then there are no more
security issues with this program than with cat(1). If, however, you let
others edit pages in your wiki, then some possible security issues do need
to be kept in mind.
+If you find a new security vulnerability, please email the maintainers
+privately instead of listing it in a public bug tracker, so that we can
+arrange for coordinated disclosure when a fix is available. The maintainers
+are [[Joey Hess|joey]] (<joey@kitenet.net>),
+[[Simon McVittie|smcv]] (<smcv@debian.org>)
+and [[Amitai Schleier|schmonz]] (<schmonz-web-ikiwiki@schmonz.com>).
+
[[!toc levels=2]]
----
## other stuff to look at
-I need to audit the git backend a bit, and have been meaning to
-see if any CRLF injection type things can be done in the CGI code.
+I have been meaning to see if any CRLF injection type things can be
+done in the CGI code.
----
for example to be used in a [[post-commit]] hook by people who cannot write
to the html pages, etc.
-If the wrapper script is made suid, then any bugs in this wrapper would be
+If the wrapper program is made suid, then any bugs in this wrapper would be
security holes. The wrapper is written as securely as I know how, is based
on code that has a history of security use long before ikiwiki, and there's
been no problem yet.
some security notes for them.
* The [[plugins/img]] plugin assumes that imagemagick/perlmagick are secure
- from malformed image attacks. Imagemagick has had security holes in the
+ from malformed image attacks for at least the formats listed in
+ `img_allowed_formats`. Imagemagick has had security holes in the
past. To be able to exploit such a hole, a user would need to be able to
upload images to the wiki.
A fix was also backported to Debian etch, as version 2.53.5. I recommend
upgrading to one of these versions if your wiki can be edited by third
parties.
+
+## javascript insertion via insufficient htmlscrubbing of comments
+
+Kevin Riggle noticed that it was not possible to configure
+`htmlscrubber_skip` to scrub comments while leaving unscubbed the text
+of eg, blog posts. Confusingly, setting it to "* and !comment(*)" did not
+scrub comments.
+
+Additionally, it was discovered that comments' html was never scrubbed during
+preview or moderation of comments with such a configuration.
+
+These problems were discovered on 12 November 2010 and fixed the same
+hour with the release of ikiwiki 3.20101112. ([[!cve CVE-2010-1673]])
+
+## javascript insertion via insufficient checking in comments
+
+Dave B noticed that attempting to comment on an illegal page name could be
+used for an XSS attack.
+
+This hole was discovered on 22 Jan 2011 and fixed the same day with
+the release of ikiwiki 3.20110122. A fix was backported to Debian squeeze,
+as version 3.20100815.5. An upgrade is recommended for sites
+with the comments plugin enabled. ([[!cve CVE-2011-0428]])
+
+## possible javascript insertion via insufficient htmlscrubbing of alternate stylesheets
+
+Giuseppe Bilotta noticed that 'meta stylesheet` directives allowed anyone
+who could upload a malicious stylesheet to a site to add it to a
+page as an alternate stylesheet, or replacing the default stylesheet.
+
+This hole was discovered on 28 Mar 2011 and fixed the same hour with
+the release of ikiwiki 3.20110328. A fix was backported to Debian squeeze,
+as version 3.20100815.6. An upgrade is recommended for sites that have
+untrusted committers, or have the attachments plugin enabled.
+([[!cve CVE-2011-1401]])
+
+## tty hijacking via ikiwiki-mass-rebuild
+
+Ludwig Nussel discovered a way for users to hijack root's tty when
+ikiwiki-mass-rebuild was run. Additionally, there was some potential
+for information disclosure via symlinks. ([[!cve CVE-2011-1408]])
+
+This hole was discovered on 8 June 2011 and fixed the same day with
+the release of ikiwiki 3.20110608. Note that the fix is dependant on
+a version of su that has a similar hole fixed. Version 4.1.5 of the shadow
+package contains the fixed su; [[!debbug 628843]] tracks fixing the hole in
+Debian. An upgrade is a must for any sites that have `ikiwiki-update-wikilist`
+installed suid (not the default), and whose admins run `ikiwiki-mass-rebuild`.
+
+## javascript insertion via meta tags
+
+Raúl Benencia discovered an additional XSS exposure in the meta plugin.
+([[!cve CVE-2012-0220]])
+
+This hole was discovered on 16 May 2012 and fixed the same day with
+the release of ikiwiki 3.20120516. A fix was backported to Debian squeeze,
+as version 3.20100815.9. An upgrade is recommended for all sites.
+
+## XSS via openid selector
+
+Raghav Bisht discovered this XSS in the openid selector. ([[!cve CVE-2015-2793]])
+
+The hole was reported on March 24th, a fix was developed on March 27th,
+and the fixed version 3.20150329 was released on the 29th. A fix was backported
+to Debian jessie as version 3.20141016.2 and to Debian wheezy as version
+3.20120629.2. An upgrade is recommended for sites using CGI and openid.
+
+## XSS via error messages
+
+CGI error messages did not escape HTML meta-characters, potentially
+allowing an attacker to carry out cross-site scripting by directing a
+user to a URL that would result in a crafted ikiwiki error message. This
+was discovered on 4 May by the ikiwiki developers, and the fixed version
+3.20160506 was released on 6 May. The same fixes were backported to Debian
+8 "jessie" in version 3.20141016.3. A backport to Debian 7 "wheezy" is
+in progress.
+
+An upgrade is recommended for sites using
+the CGI. ([[!cve CVE-2016-4561]], OVE-20160505-0012)
+
+## ImageMagick CVE-2016–3714 ("ImageTragick")
+
+ikiwiki 3.20160506 and 3.20141016.3 attempt to mitigate
+[[!cve CVE-2016-3714]], and any
+future ImageMagick vulnerabilities that resemble it, by restricting the
+image formats that the [[ikiwiki/directive/img]] directive is willing to
+resize. An upgrade is recommended for sites where an untrusted user is
+able to attach images. Upgrading ImageMagick to a version where
+CVE-2016-3714 has been fixed is also recommended, but at the time of
+writing no such version is available.
+
+## Perl CVE-2016-1238 (current working directory in search path)
+
+ikiwiki 3.20160728 attempts to mitigate [[!cve CVE-2016-1238]] by
+removing `'.'` from the Perl library search path. An attacker with write
+access to ikiwiki's current working directory could potentially use this
+vulnerability to execute arbitrary Perl code. An upgrade is recommended
+for sites where an untrusted user is able to attach files with arbitrary
+names and/or run a setuid ikiwiki wrapper with a working directory of
+their choice.
+
+## Editing restriction bypass for git revert
+
+intrigeri discovered that a web or git user could revert a change to a
+page they are not allowed to edit, if the change being reverted was made
+before the page was moved from a location where that user had permission
+to edit it. For example, if a file is moved from `drafts/policy.mdwn`
+(editable by less-trusted users) to `policy.mdwn` (only editable
+by more-trusted users), a less-trusted user could revert a change
+that was made to `drafts/policy.mdwn` prior to that move, and it would
+result in `policy.mdwn` being altered.
+
+This affects sites with the `git` VCS and the `recentchanges` plugin,
+which are both used in most ikiwiki installations.
+
+This bug was reported on 2016-12-17. A partially fixed version
+3.20161219 was released on 2016-12-19, but the solution used in that
+version was not effective with git versions older than 2.8.0.
+A more complete fix was released on 2016-12-29 in version 3.20161229.
+A backport to Debian 8 'jessie' is in progress.
+
+([[!cve CVE-2016-10026]] represents the original vulnerability.
+[[!cve CVE-2016-9645]]/OVE-20161226-0002 represents the vulnerability
+in 3.20161219 caused by the incomplete fix.)
+
+## Commit metadata forgery via CGI::FormBuilder context-dependent APIs
+
+When CGI::FormBuilder->field("foo") is called in list context (and
+in particular in the arguments to a subroutine that takes named
+arguments), it can return zero or more values for foo from the CGI
+request, rather than the expected single value. This breaks the usual
+Perl parsing convention for named arguments, similar to CVE-2014-1572
+in Bugzilla (which was caused by a similar API design issue in CGI.pm).
+
+In ikiwiki, this appears to have been exploitable in two places, both
+of them relatively minor:
+
+* in the comments plugin, an attacker who was able to post a comment
+ could give it a user-specified author and author-URL even if the wiki
+ configuration did not allow for that, by crafting multiple values
+ for other fields
+* in the editpage plugin, an attacker who was able to edit a page
+ could potentially forge commit authorship (attribute their edit to
+ someone else) by crafting multiple values for the rcsinfo field
+
+This was fixed in ikiwiki 3.20161229. A backport to Debian 8
+'jessie' is in progress.
+
+([[!cve CVE-2016-9646]]/OVE-20161226-0001)