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# COMPASS SECURITY ADVISORY
# http://www.csnc.ch/en/downloads/advisories.html
#
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#
# Product:  Leed (Light Feed)
# Vendor:   Valentin CARRUESCO aka Idleman
# CSNC ID:  CSNC-2013-005 (SQL Injection), CSNC-2013-006 (CSRF), CSNC-2013-007 (Authentication Bypass)
# CVD ID:   CVE-2013-2627 (SQL Injection), CVE-2013-2628 (CSRF), CVE-2013-2629 (Authentication Bypass)
# Subject:  Multiple vulnerabilities (see above)
# Risk:     High
# Effect:   Remotely exploitable
# Author:   Alexandre Herzog <alexandre.herzog@csnc.ch>
# Date:     18.12.2013
#
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Introduction:
-------------
Leed is a lightweight RSS/ATOM aggregator based on PHP. It can be hosted 
on any server supporting PHP and aims to be an alternative to Google 
Reader and its substitutes. [1] 


 
Technical Description
---------------------

1. SQL injection (CSNC-2013-005 / CVE-2013-2627)
The SQL injection is within the ID parameter of 
leed/action.php?action=removeFolder&id=-1 as user input does not get 
properly escaped. Escaping is otherwise done consistently across the 
remaining of the audited code. Exploiting this issue is tricky due to 
the HTML encoding, but not impossible, e.g. 
If select @@version returns '5.0.84-log' on your database,
CAST(@@version as signed) will return 5
Injection parameter (before encoding) would e.g. be
IF(CAST(@@version as signed) in(5),BENCHMARK(2000000,SHA1(0)),-1)
This blind SQL will last ~5 seconds on my installation as the condition
is true. This way, you could extract information one by one from the
mysql tables.

2. Authorization bypasses in action.php (CSNC-2013-007 / CVE-2013-2629)
The following actions can be called anonymously, as the $myUser variable
isn't verified:
- importForm
- importFeed
- addFavorite
- removeFavorite

3. Missing anti cross-site request forgery token (CSNC-2013-006 / CVE-2013-2628)
None of the actions done within action.php requires a token to defeat CSRF.
This means malicious action can be executed under the identity of a logged
in Leed admin if the victim clicks on a malicious link or visits a website
under the attacker's control.


Workaround / Fix:
-----------------
Upgrade to the latest available version of Leed.


Timeline:
---------
2013-12-18:     Public disclosure date
2013-03-19:     GIT commit of the fixes
2013-03-19:     Initial vendor response
2013-03-19:     Discovery by Alexandre Herzog & initial vendor notification


References:
-----------
[1] http://projet.idleman.fr/leed/

--
Alexandre Herzog, IT Security Analyst, Compass Security AG
Werkstrasse 20, 8645 Jona, Switzerland
Schauplatzgasse 39, 3011 Bern, Switzerland
Tel: +41 55 214 41 66
http://www.csnc.ch/