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 Geeklog 1.7.1 <= Cross Site Scripting Vulnerability
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1. OVERVIEW

The Geeklog was vulnerable to Cross Site Scripting in its
administration backend.


2. BACKGROUND

Geeklog is a PHP/MySQL based application for managing dynamic web content.
"Out of the box", it is a blog engine, or a CMS with support for
comments, trackbacks,
multiple syndication formats, spam protection, and all the other vital
features of such a system.


3. VULNERABILITY DESCRIPTION

User supplied input is not probably sanitized in the "subgroup" and "conf_group"
parameters when the configuration settings are saved in
/admin/configuration.php.
Attackers who manage to get/bypass anti-csrf token (_glsectoken) via
other means can effectively perform XSS against admin users.


4. VERSIONS AFFECTED

1.7.1 and lower


5. PROOF-OF-CONCEPT/EXPLOIT

[Request]

POST /geeklog/admin/configuration.php HTTP/1.1

_glsectoken=&conf_group=Core'"--></script><script>alert(/XSS/)</script>&subgroup='"--></script><script>alert(/XSS/)</script>

[/Request]


6. SOLUTION

Upgrade to 1.7.1sr1


7. VENDOR

Geeklog Development Team
http://www.geeklog.net/


8. CREDIT

This vulnerability was discovered by Aung Khant, http://yehg.net, YGN
Ethical Hacker Group, Myanmar.


9. DISCLOSURE TIME-LINE

2010-12-31: notified vendor
2011-01-02: vendor released fixed version
2011-01-04: vulnerability disclosed


10. REFERENCES

Original Advisory URL:
http://yehg.net/lab/pr0js/advisories/[geeklog1.7.1]_cross_site_scripting
Vendor Advisory: http://www.geeklog.net/article.php/geeklog-1.7.1sr1
About Geeklog: http://www.geeklog.net/docs/english/#introduction
http://stephensclafani.com/2009/05/26/exploiting-unexploitable-xss/
http://kuza55.blogspot.com/2008/02/exploiting-csrf-protected-xss.html

#yehg [2011-01-04]

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Best regards,
YGN Ethical Hacker Group
Yangon, Myanmar
http://yehg.net
Our Lab | http://yehg.net/lab
Our Directory | http://yehg.net/hwd