others edit pages in your wiki, then some possible security issues do need
to be kept in mind.
+# Probable holes
+
## html attacks
ikiwiki does not attempt to do any santization of the html on the wiki.
-MarkDown allows embedding of arbitrary html into a markdown document. If
+[[MarkDown]] allows embedding of arbitrary html into a markdown document. If
you let anyone else edit files on the wiki, then anyone can have fun exploiting
the web browser bug of the day. This type of attack is typically referred
to as an XSS attack ([google](http://www.google.com/search?q=xss+attack)).
If it enounters a file type it does not understand, ikiwiki just copies it
into place. So if you let users add any kind of file they like, they can
-upload images, movies, windows executables, etc. If these files exploit
-security holes in the browser of someone who's viewing the wiki, that can
-be a security problem.
-
-## exploting ikiwiki with bad content
-
-Someone could add bad content to the wiki and hope to exploit ikiwiki.
-Note that ikiwiki runs with perl taint checks on, so this is unlikely;
-the only data that is not subject to full taint checking is the names of
-files, and filenames are sanitised.
-
-## cgi scripts
+upload images, movies, windows executables, css files, etc. If these files exploit security holes in the browser of someone who's viewing the wiki, that can be a security problem.
-ikiwiki does not allow cgi scripts to be published as part of the wiki. Or
-rather, the script is published, but it's not marked executable, so
-hopefully your web server will not run it.
+Of course nobody else seems to worry about this in other wikis, so should we?
## web server attacks
server parsed html files), then if you let anyone else add files to the wiki,
they can try to use this to exploit your web server.
-## --gen-wrapper might generate insecure wrappers
-
-ikiwiki --gen-wrapper is intended to generate a wrapper program that
-runs ikiwiki to update a given wiki. The wrapper can in turn be made suid,
-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
-security holes. The wrapper is written as securely as I know how and
-there's been no problem yet.
-
## symlink attacks
Could a committer trick ikiwiki into following a symlink and operating on
would both fix this and is a good idea in general. With locking, an
attacker couldn't get ikiwiki to svn up while another instance was running.
-Even with locking, if an attacker has local write access to the checkout,
-they could still fool ikiwiki using similar races. So it's best if only one
-person can ever write to the checkout that ikiwiki compiles the moo from.
+## multiple accessors of wiki source directory
+
+If multiple people can write to the source directory ikiwiki is using, then
+one can cause trouble for the other when they run ikiwiki through symlink
+sttacks.
+
+So it's best if only one person can ever write to the checkout that ikiwiki
+compiles the moo from.
-## cgi security
+## webserver symlink attacks
+
+If someone checks in a symlink to /etc/passwd, ikiwiki would publish that.
+To aoid this, ikiwiki will need to avoid reading files that are symlinks.
+TODO and note discussion of races above.
+
+## cgi data security
When ikiwiki runs as a cgi to edit a page, it is passed the name of the
page to edit. It has to make sure to sanitise this page, to prevent eg,
such as subversion dotfiles. This is done by sanitising the filename
removing unallowed characters, then making sure it doesn't start with "/"
or contain ".." or "/.svn/". Annoyingly ad-hoc, this kind of code is where
-security holes breed.
+security holes breed. It needs a test suite at the very least.
+
+## cgi password security
+
+Login to the wiki involves sending a password in cleartext over the net.
+Cracking the password only allows editing the moo as that user though.
+If you care, you can use https, I suppose.
+
+## CGI::Session security
+
+Is CGI::Session secure? Well, it writes the session files world-readable,
+which could be used by a local attacker to take over someone's session.
+
+I have no idea if CGI::Session writes session files securely to /tmp.
+ikiwiki makes it write them to a directory it controls (but see "multiple
+accessors of wiki source directory" above).
+
+----
+
+# Probable non-holes
+
+## exploting ikiwiki with bad content
+
+Someone could add bad content to the wiki and hope to exploit ikiwiki.
+Note that ikiwiki runs with perl taint checks on, so this is unlikely.
+
+## publishing cgi scripts
+
+ikiwiki does not allow cgi scripts to be published as part of the wiki. Or
+rather, the script is published, but it's not marked executable, so
+hopefully your web server will not run it.
+
+## suid wrappers
+
+ikiwiki --wrapper is intended to generate a wrapper program that
+runs ikiwiki to update a given wiki. The wrapper can in turn be made suid,
+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
+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.
+
+## shell exploits
+
+ikiwiki does not expose untrusted data to the shell. In fact it doesn't use system() at all, and the only use of backticks is on data supplied by the wiki admin. And it runs with taint checks on of course..