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SilverStripe CMS 2.4.7 <= Arbitrary URL Redirection
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1. OVERVIEW

SilverStripe 2.4.7 and lower versions are vulnerable to Open URL Redirection.


2. BACKGROUND

SilverStripe CMS is easy for both developers and content authors to work with. The SilverStripe Framework keeps the code tucked away neatly so that it can be accessed easily by programmers but does not get in the way of content authors. 


3. VULNERABILITY DESCRIPTION

SilverStripe CMS contains a flaw that allows a remote cross site redirection attack. This flaw exists because the application does not validate the "BackURL" parameter upon submission to the "/index.php/Security/login" script. This could allow a user to create a specially crafted URL, that if clicked, would redirect a victim from the intended legitimate web site to an arbitrary web site of the attacker's choosing.


4. VERSIONS AFFECTED

Tested on 2.4.7


5. PROOF-OF-CONCEPT/EXPLOIT

http://localhost/index.php/Security/login?BackURL=//yehg.net


6. SOLUTION

Upgrade to the latest 3.x version.


7. VENDOR

SilverStripe Development Team
http://www.silverstripe.org/


8. CREDIT

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


9. DISCLOSURE TIME-LINE

2012-02-06: notified vendor
2012-10-15: vulnerability disclosed


10. REFERENCES

Original Advisory URL: http://yehg.net/lab/pr0js/advisories/%5BSilverStripe_2.4.7%5D_url_redirection

#yehg [2012-10-15]