Title : Shaarli Vulnerabilities
Author : @erwan_lr | @_WPScan_
Vendor : http://sebsauvage.net/wiki/doku.php?id=php:shaarli
Download : https://github.com/sebsauvage/Shaarli/archive/master.zip |
http://sebsauvage.net/files/shaarli_0.0.40beta.zip
Affected versions : master-705F835, 0.0.40-beta (versions below may also
be vulnerable)
Vulnerabilities : Persistent XSS & Unvalidated Redirects and Forwards
Persistent XSS :
- During the instalation or configuration modification, the title field
is vulnerable. e.g <script>alert(1)</script>
Quotes can not be used because of var_export(), but String.fromCharCode
works
- The url field of a link is vulnerable :
When there is no redirector : javascript:alert(1)
Then, the code is triggered when a user click the url of a link
Or with a classic XSS : "><script>alert(1)</script>
Unvalidated Redirects and Forwards :
A request with the param linksperpage or privateonly can be used to
redirect a user to an arbitrary referer
e.g
GET /Audit/Shaarli/master-705f835/?linksperpage=10 HTTP/1.1
Host: 127.0.0.1
Referer: https://duckduckgo.com
History :
March 2, 2013
- Vendor contacted
Shaarli uses light Javascript in its normal operation, and some jQuery
for some features (autocomplete in tags, QR-Code popup...).
jQuery can be slow on small computers. An option has been added in
configuration screen to disable javascript features which are hard on
CPU.
(Note that the Picture Wall is awfully heavy *without* jQuery.)
(Side note: A *LOT* of users want Shaarli to work without javasript at
all, if possible. That's why I try to use as few javascript as possible:
It keeps Shaarli pages fast.)
In the RSS specifications, the "link" tags contains the URL to follow,
and the "guid" contains a unique identifier (which may or may not be an
URL).
RSS clients should always use "link" to follow the link (and most do),
but Thunderbird uses the "guid" if it find a valid URL inside (and only
falls back to "link" if "guid" is not an URL).
I have patched the RSS feed so that Thunderbird ignores the URL in guid.
This is necessary because some hosts do not have a properly set
session.save_path parameter in php config, or do not have write access
to the directory.
This corrects the session problem with some browsers when Shaarli is
hosted on a sub-domain. Please tell me if this corrects login problems
if you had one.
Knah Tsaeb
Sébastien SAUVAGE
David Sferruzza
Mathieu Chabanon