aushack.com - Vulnerability Advisory
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Release Date:
22-Sep-2006
Software:
Squiz - My Source and My Source Matrix
http://www.squiz.net.au
"MySource Matrix is the newest version of the popular MySource CMS,
purpose built for enterprise level installations. It boasts all the
features of high-end systems such as highly configurable workflow,
a powerful integrated search engine, intuitive front-end editing, true
rollback and much more."
Versions affected:
MySource Matrix 3.8 and below, MySource 2.x.
Vulnerability discovered:
MySource Matrix may be used as an unauthorised HTTP proxy (and XSS).
Vulnerability impact:
Low - An anonymous user may use the MySource based website as a proxy.
Additionally, proxied bandwidth may be at great financial expense.
Remote content may contain JavaScript which is client executed.
Vulnerability information
A function of the software 'sq_remote_page_url' allows inclusion of remote
content in the body of the website.
Example: (wrapped)
http://www.mysource-example.com.au/$page?sq_remote_page_action=
fetch_url&sq_remote_page_url=http://www.google.com.au
... where '$page' is a valid CMS reference, e.g. 'about_us'.
This will return the Google website, encapsulated in the header
and footer HTML of the www.mysource-example.com.au site.
The remote page may contain JavaScript for XSS purposes, e.g. cookies.
Remote PHP inclusion does not appear to be possible (returns % hex value).
One could write a script to enable a world wide anonymous proxy array.
Solution:
The vendor does not consider this a vulnerability. Newer versions of the
software include a function 'sq_content_src' to hide the URL (Base64),
in addition to use of a string whitelist to permit inclusion, for example:
if whitelist = http://www.trust-content.com/index?id=*, where * = <wildcard>
ok = http://www.trust-content.com/index?id=1234
bad = http://www.trust-content.com/index?ref=1234
Note that whilst the URL is Base64 encoded, this does not necessarily mean
that whitelists are used. Future releases may be proxied via:
http://www.mysource-example.com.au/$page?
sq_content_src=aHR0cDovL3d3dy5nb29nbGUuY29tLmF1
References:
aushack.com advisory
http://www.aushack.com/advisories/200607-mysourcematrix.txt
Credit:
Patrick Webster ( patrick (at) aushack (dot) com [email concealed] )
Disclosure timeline:
27-Apr-2006 - Discovered during audit, Squiz notified shortly after.
07-Jun-2006 - Sent security patch query to Squiz developers.
09-Jun-2006 - Squiz response - use whitelist function.
22-Sep-2006 - Public disclosure.
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