Move about: fix to version 2.31.3 in the changelog

[git.ikiwiki.info.git] / doc / security.mdwn

diff --git a/doc/security.mdwn b/doc/security.mdwn
index a1c2120ce9abd34287c4e53dc495c007d1da8782..d9e0f655b2276df9da619f8597f138aab99371c8 100644 (file)
--- a/doc/security.mdwn
+++ b/doc/security.mdwn
@@ -41,32 +41,39 @@ who's viewing the wiki, that can be a security problem.
 
 Of course nobody else seems to worry about this in other wikis, so should we?
 
 
 Of course nobody else seems to worry about this in other wikis, so should we?
 

-Currently only people with direct svn commit access can upload such files
-(and if you wanted to you could block that with a svn pre-commit hook).
+Currently only people with direct commit access can upload such files
+(and if you wanted to you could block that with a pre-commit hook).

 Users with only web commit access are limited to editing pages as ikiwiki
 doesn't support file uploads from browsers (yet), so they can't exploit
 this.
 
 Users with only web commit access are limited to editing pages as ikiwiki
 doesn't support file uploads from browsers (yet), so they can't exploit
 this.
 

+It is possible to embed an image in a page edited over the web, by using
+`img src="data:image/png;"`. Ikiwiki's htmlscrubber only allows `data:`
+urls to be used for `image/*` mime types. It's possible that some broken
+browser might ignore the mime type and if the data provided is not an
+image, instead run it as javascript, or something evil like that. Hopefully
+not many browsers are that broken.
+

 ## multiple accessors of wiki directory
 
 ## multiple accessors of wiki directory
 

-If multiple people can write to the source directory ikiwiki is using, or
-to the destination directory it writes files to, then one can cause trouble
-for the other when they run ikiwiki through symlink attacks.
+If multiple people can directly write to the source directory ikiwiki is
+using, or to the destination directory it writes files to, then one can
+cause trouble for the other when they run ikiwiki through symlink attacks.

 
 

-So it's best if only one person can ever write to those directories.
+So it's best if only one person can ever directly write to those directories.

 
 ## setup files
 
 
 ## setup files
 

-Setup files are not safe to keep in subversion with the rest of the wiki.
-Just don't do it. [[ikiwiki.setup]] is *not* used as the setup file for
-this wiki, BTW.
+Setup files are not safe to keep in the same revision control repository
+with the rest of the wiki. Just don't do it. [[ikiwiki.setup]] is *not*
+used as the setup file for this wiki, BTW.

 
 

-## page locking can be bypassed via direct svn commits
+## page locking can be bypassed via direct commits

 
 

-A locked page can only be edited on the web by an admin, but
-anyone who is allowed to commit direct to svn can bypass this. This is by
-design, although a subversion pre-commit hook could be used to prevent
-editing of locked pages when using subversion, if you really need to.
+A locked page can only be edited on the web by an admin, but anyone who is
+allowed to commit directly to the repository can bypass this. This is by
+design, although a pre-commit hook could be used to prevent editing of
+locked pages, if you really need to.

 
 ## web server attacks
 
 
 ## web server attacks
 


@@ -122,8 +129,8 @@ page to edit. It has to make sure to sanitise this page, to prevent eg,
 editing of ../../../foo, or editing of files that are not part of the wiki,
 such as subversion dotfiles. This is done by sanitising the filename
 removing unallowed characters, then making sure it doesn't start with "/"
 editing of ../../../foo, or editing of files that are not part of the wiki,
 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. It needs a test suite at the very least.
+or contain ".." or "/.svn/", etc. Annoyingly ad-hoc, this kind of code is
+where security holes breed. It needs a test suite at the very least.

 
 ## CGI::Session security
 
 
 ## CGI::Session security
 


@@ -204,13 +211,13 @@ wouldn't see.
 
 To avoid this, ikiwiki will skip over symlinks when scanning for pages, and
 uses locking to prevent more than one instance running at a time. The lock
 
 To avoid this, ikiwiki will skip over symlinks when scanning for pages, and
 uses locking to prevent more than one instance running at a time. The lock

-prevents one ikiwiki from running a svn up at the wrong time to race
-another ikiwiki. So only attackers who can write to the working copy on
-their own can race it.
+prevents one ikiwiki from running a svn up/git pull/etc at the wrong time
+to race another ikiwiki. So only attackers who can write to the working
+copy on their own can race it.

 
 ## symlink + cgi attacks
 
 
 ## symlink + cgi attacks
 

-Similarly, a svn commit of a symlink could be made, ikiwiki ignores it
+Similarly, a commit of a symlink could be made, ikiwiki ignores it

 because of the above, but the symlink is still there, and then you edit the
 page from the web, which follows the symlink when reading the page
 (exposing the content), and again when saving the changed page (changing
 because of the above, but the symlink is still there, and then you edit the
 page from the web, which follows the symlink when reading the page
 (exposing the content), and again when saving the changed page (changing


@@ -341,7 +348,17 @@ There are at least two configurations where this is exploitable:
   notice.
 
 This security hole was discovered on 26 November 2007 and fixed the same
   notice.
 
 This security hole was discovered on 26 November 2007 and fixed the same

-da with the release of ikiwiki 2.14. I recommend upgrading to this version
+day with the release of ikiwiki 2.14. I recommend upgrading to this version

 if your wiki can be committed to by third parties. Alternatively, don't use
 a trailing slash in the srcdir, and avoid the (unusual) configurations that
 allow the security hole to be exploited.
 if your wiki can be committed to by third parties. Alternatively, don't use
 a trailing slash in the srcdir, and avoid the (unusual) configurations that
 allow the security hole to be exploited.

+
+## javascript insertion via uris
+
+The htmlscrubber did not block javascript in uris. This was fixed by adding
+a whitelist of valid uri types, which does not include javascript.
+
+This hole was discovered on 10 February 2008 and fixed the same day
+with the release of ikiwiki 2.31.1. A fix was also backported to Debian etch,
+as version 1.33.4. I recommend upgrading to one of these versions if your
+wiki can be edited by third parties.